Index: Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Service/ClosingStructuresCalculationActivity.cs
===================================================================
diff -u -rf71fb2faaae836236b85a1c3a4483f6aee4f4d88 -rcdc1bc16334dad7a675276648c42ac6fab5ffdfb
--- Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Service/ClosingStructuresCalculationActivity.cs	(.../ClosingStructuresCalculationActivity.cs)	(revision f71fb2faaae836236b85a1c3a4483f6aee4f4d88)
+++ Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Service/ClosingStructuresCalculationActivity.cs	(.../ClosingStructuresCalculationActivity.cs)	(revision cdc1bc16334dad7a675276648c42ac6fab5ffdfb)
@@ -23,6 +23,7 @@
 using Core.Common.Base.Service;
 using Ringtoets.ClosingStructures.Data;
 using Ringtoets.Common.Data.AssessmentSection;
+using Ringtoets.Common.Data.Hydraulics;
 using Ringtoets.Common.Data.Structures;
 using Ringtoets.HydraRing.Calculation.Activities;
 using RingtoetsCommonServiceResources = Ringtoets.Common.Service.Properties.Resources;
@@ -95,7 +96,8 @@
                                          failureMechanism.GeneralInput.N,
                                          assessmentSection.FailureMechanismContribution.Norm,
                                          failureMechanism.Contribution,
-                                         hydraulicBoundaryDatabaseFilePath);
+                                         hydraulicBoundaryDatabaseFilePath,
+                                         assessmentSection.HydraulicBoundaryDatabase.EffectivePreprocessorDirectory());
         }
 
         protected override void OnCancel()
Index: Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.Service.Test/ClosingStructuresCalculationServiceTest.cs
===================================================================
diff -u -r3b5e1adef92f7ce3cf8d896ec310e9203f0e8d7d -rcdc1bc16334dad7a675276648c42ac6fab5ffdfb
--- Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.Service.Test/ClosingStructuresCalculationServiceTest.cs	(.../ClosingStructuresCalculationServiceTest.cs)	(revision 3b5e1adef92f7ce3cf8d896ec310e9203f0e8d7d)
+++ Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.Service.Test/ClosingStructuresCalculationServiceTest.cs	(.../ClosingStructuresCalculationServiceTest.cs)	(revision cdc1bc16334dad7a675276648c42ac6fab5ffdfb)
@@ -51,6 +51,7 @@
     {
         private static readonly string testDataPath = TestHelper.GetTestDataPath(TestDataPath.Ringtoets.Integration.Service, "HydraRingCalculation");
         private static readonly string validFilePath = Path.Combine(testDataPath, "HRD dutch coast south.sqlite");
+        private static readonly string preprocessorDirectory = Path.Combine(testDataPath, "Preprocessor");
 
         [Test]
         public void Constructor_ExpectedValues()
@@ -363,7 +364,8 @@
                                                             failureMechanism.GeneralInput.N,
                                                             assessmentSection.FailureMechanismContribution.Norm,
                                                             failureMechanism.Contribution,
-                                                            validFilePath);
+                                                            validFilePath,
+                                                            preprocessorDirectory);
 
                 // Assert
                 const string expectedMessage = "The value of argument 'structureInput' (100) is invalid for Enum type 'ClosingStructureInflowModelType'.";
@@ -389,7 +391,7 @@
 
             var calculator = new TestStructuresCalculator<StructuresClosureCalculationInput>();
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -414,7 +416,8 @@
                                                                     failureMechanism.GeneralInput.N,
                                                                     assessmentSection.FailureMechanismContribution.Norm,
                                                                     failureMechanism.Contribution,
-                                                                    validFilePath);
+                                                                    validFilePath,
+                                                                    preprocessorDirectory);
 
                 // Assert
                 StructuresClosureCalculationInput[] calculationInputs = calculator.ReceivedInputs.ToArray();
@@ -470,7 +473,7 @@
 
             var calculator = new TestStructuresCalculator<StructuresClosureCalculationInput>();
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -496,7 +499,8 @@
                                                                     failureMechanism.GeneralInput.N,
                                                                     assessmentSection.FailureMechanismContribution.Norm,
                                                                     failureMechanism.Contribution,
-                                                                    validFilePath);
+                                                                    validFilePath,
+                                                                    preprocessorDirectory);
 
                 // Assert
                 StructuresClosureCalculationInput[] calculationInputs = calculator.ReceivedInputs.ToArray();
@@ -550,7 +554,7 @@
                                                                                                        mockRepository);
             var calculator = new TestStructuresCalculator<StructuresClosureCalculationInput>();
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -576,7 +580,8 @@
                                                                     failureMechanism.GeneralInput.N,
                                                                     assessmentSection.FailureMechanismContribution.Norm,
                                                                     failureMechanism.Contribution,
-                                                                    validFilePath);
+                                                                    validFilePath,
+                                                                    preprocessorDirectory);
 
                 // Assert
                 StructuresClosureCalculationInput[] calculationInputs = calculator.ReceivedInputs.ToArray();
@@ -632,7 +637,7 @@
             IAssessmentSection assessmentSection = AssessmentSectionHelper.CreateAssessmentSectionStub(failureMechanism,
                                                                                                        mockRepository);
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(new TestStructuresCalculator<StructuresClosureCalculationInput>());
             mockRepository.ReplayAll();
 
@@ -671,7 +676,8 @@
                                                                                         failureMechanism.GeneralInput.N,
                                                                                         assessmentSection.FailureMechanismContribution.Norm,
                                                                                         failureMechanism.Contribution,
-                                                                                        validFilePath);
+                                                                                        validFilePath,
+                                                                                        preprocessorDirectory);
 
                 // Assert
                 TestHelper.AssertLogMessages(call, messages =>
@@ -708,7 +714,7 @@
                 EndInFailure = true
             };
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -734,7 +740,8 @@
                                                                             failureMechanism.GeneralInput.N,
                                                                             assessmentSection.FailureMechanismContribution.Norm,
                                                                             failureMechanism.Contribution,
-                                                                            validFilePath);
+                                                                            validFilePath,
+                                                                            preprocessorDirectory);
                     }
                     catch (HydraRingCalculationException)
                     {
@@ -777,7 +784,7 @@
                 EndInFailure = true
             };
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -803,7 +810,8 @@
                                                                             failureMechanism.GeneralInput.N,
                                                                             assessmentSection.FailureMechanismContribution.Norm,
                                                                             failureMechanism.Contribution,
-                                                                            validFilePath);
+                                                                            validFilePath,
+                                                                            preprocessorDirectory);
                     }
                     catch (HydraRingCalculationException)
                     {
@@ -847,7 +855,7 @@
                 LastErrorFileContent = "An error occurred"
             };
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresClosureCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -874,7 +882,8 @@
                                                                             failureMechanism.GeneralInput.N,
                                                                             assessmentSection.FailureMechanismContribution.Norm,
                                                                             failureMechanism.Contribution,
-                                                                            validFilePath);
+                                                                            validFilePath,
+                                                                            preprocessorDirectory);
                     }
                     catch (HydraRingCalculationException e)
                     {
Index: Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Service/HeightStructuresCalculationActivity.cs
===================================================================
diff -u -rf71fb2faaae836236b85a1c3a4483f6aee4f4d88 -rcdc1bc16334dad7a675276648c42ac6fab5ffdfb
--- Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Service/HeightStructuresCalculationActivity.cs	(.../HeightStructuresCalculationActivity.cs)	(revision f71fb2faaae836236b85a1c3a4483f6aee4f4d88)
+++ Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Service/HeightStructuresCalculationActivity.cs	(.../HeightStructuresCalculationActivity.cs)	(revision cdc1bc16334dad7a675276648c42ac6fab5ffdfb)
@@ -22,6 +22,7 @@
 using System;
 using Core.Common.Base.Service;
 using Ringtoets.Common.Data.AssessmentSection;
+using Ringtoets.Common.Data.Hydraulics;
 using Ringtoets.Common.Data.Structures;
 using Ringtoets.HeightStructures.Data;
 using Ringtoets.HydraRing.Calculation.Activities;
@@ -92,7 +93,8 @@
                                          failureMechanism.GeneralInput.N,
                                          assessmentSection.FailureMechanismContribution.Norm,
                                          failureMechanism.Contribution,
-                                         hydraulicBoundaryDatabaseFilePath);
+                                         hydraulicBoundaryDatabaseFilePath,
+                                         assessmentSection.HydraulicBoundaryDatabase.EffectivePreprocessorDirectory());
         }
 
         protected override void OnCancel()
Index: Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.Service.Test/HeightStructuresCalculationServiceTest.cs
===================================================================
diff -u -r3b5e1adef92f7ce3cf8d896ec310e9203f0e8d7d -rcdc1bc16334dad7a675276648c42ac6fab5ffdfb
--- Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.Service.Test/HeightStructuresCalculationServiceTest.cs	(.../HeightStructuresCalculationServiceTest.cs)	(revision 3b5e1adef92f7ce3cf8d896ec310e9203f0e8d7d)
+++ Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.Service.Test/HeightStructuresCalculationServiceTest.cs	(.../HeightStructuresCalculationServiceTest.cs)	(revision cdc1bc16334dad7a675276648c42ac6fab5ffdfb)
@@ -51,6 +51,7 @@
     {
         private static readonly string testDataPath = TestHelper.GetTestDataPath(TestDataPath.Ringtoets.Integration.Service, "HydraRingCalculation");
         private static readonly string validFilePath = Path.Combine(testDataPath, "HRD dutch coast south.sqlite");
+        private static readonly string preprocessorDirectory = Path.Combine(testDataPath, "Preprocessor");
 
         [Test]
         public void Constructor_ExpectedValues()
@@ -395,7 +396,7 @@
             IAssessmentSection assessmentSection = AssessmentSectionHelper.CreateAssessmentSectionStub(failureMechanism, mockRepository);
 
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresOvertoppingCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresOvertoppingCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(new TestStructuresCalculator<StructuresOvertoppingCalculationInput>());
             mockRepository.ReplayAll();
 
@@ -433,7 +434,8 @@
                                                                                        failureMechanism.GeneralInput.N,
                                                                                        assessmentSection.FailureMechanismContribution.Norm,
                                                                                        failureMechanism.Contribution,
-                                                                                       validFilePath);
+                                                                                       validFilePath,
+                                                                                       preprocessorDirectory);
 
                 // Assert
                 TestHelper.AssertLogMessages(call, messages =>
@@ -469,7 +471,7 @@
             IAssessmentSection assessmentSection = AssessmentSectionHelper.CreateAssessmentSectionStub(failureMechanism, mockRepository);
 
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresOvertoppingCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresOvertoppingCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(new TestStructuresCalculator<StructuresOvertoppingCalculationInput>());
             mockRepository.ReplayAll();
 
@@ -492,7 +494,8 @@
                                                                                        failureMechanism.GeneralInput.N,
                                                                                        assessmentSection.FailureMechanismContribution.Norm,
                                                                                        failureMechanism.Contribution,
-                                                                                       validFilePath);
+                                                                                       validFilePath,
+                                                                                       preprocessorDirectory);
 
                 // Assert
                 TestHelper.AssertLogMessages(call, messages =>
@@ -522,7 +525,7 @@
 
             var calculator = new TestStructuresCalculator<StructuresOvertoppingCalculationInput>();
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresOvertoppingCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresOvertoppingCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -547,7 +550,8 @@
                                                                    failureMechanism.GeneralInput.N,
                                                                    assessmentSection.FailureMechanismContribution.Norm,
                                                                    failureMechanism.Contribution,
-                                                                   validFilePath);
+                                                                   validFilePath,
+                                                                   preprocessorDirectory);
 
                 // Assert
                 StructuresOvertoppingCalculationInput[] overtoppingCalculationInputs = calculator.ReceivedInputs.ToArray();
@@ -604,7 +608,7 @@
                 LastErrorFileContent = "An error occurred"
             };
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresOvertoppingCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresOvertoppingCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -630,7 +634,8 @@
                                                                            failureMechanism.GeneralInput.N,
                                                                            assessmentSection.FailureMechanismContribution.Norm,
                                                                            failureMechanism.Contribution,
-                                                                           validFilePath);
+                                                                           validFilePath,
+                                                                           preprocessorDirectory);
                     }
                     catch (HydraRingCalculationException)
                     {
@@ -674,7 +679,7 @@
                 EndInFailure = true
             };
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresOvertoppingCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresOvertoppingCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -700,7 +705,8 @@
                                                                            failureMechanism.GeneralInput.N,
                                                                            assessmentSection.FailureMechanismContribution.Norm,
                                                                            failureMechanism.Contribution,
-                                                                           validFilePath);
+                                                                           validFilePath,
+                                                                           preprocessorDirectory);
                     }
                     catch (HydraRingCalculationException)
                     {
@@ -744,7 +750,7 @@
                 LastErrorFileContent = "An error occurred"
             };
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresOvertoppingCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresOvertoppingCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -771,7 +777,8 @@
                                                                            failureMechanism.GeneralInput.N,
                                                                            assessmentSection.FailureMechanismContribution.Norm,
                                                                            failureMechanism.Contribution,
-                                                                           validFilePath);
+                                                                           validFilePath,
+                                                                           preprocessorDirectory);
                     }
                     catch (HydraRingCalculationException e)
                     {
Index: Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.Service/StabilityPointStructuresCalculationActivity.cs
===================================================================
diff -u -rf71fb2faaae836236b85a1c3a4483f6aee4f4d88 -rcdc1bc16334dad7a675276648c42ac6fab5ffdfb
--- Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.Service/StabilityPointStructuresCalculationActivity.cs	(.../StabilityPointStructuresCalculationActivity.cs)	(revision f71fb2faaae836236b85a1c3a4483f6aee4f4d88)
+++ Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.Service/StabilityPointStructuresCalculationActivity.cs	(.../StabilityPointStructuresCalculationActivity.cs)	(revision cdc1bc16334dad7a675276648c42ac6fab5ffdfb)
@@ -22,6 +22,7 @@
 using System;
 using Core.Common.Base.Service;
 using Ringtoets.Common.Data.AssessmentSection;
+using Ringtoets.Common.Data.Hydraulics;
 using Ringtoets.Common.Data.Structures;
 using Ringtoets.HydraRing.Calculation.Activities;
 using Ringtoets.StabilityPointStructures.Data;
@@ -95,7 +96,8 @@
                                          failureMechanism.GeneralInput.N,
                                          assessmentSection.FailureMechanismContribution.Norm,
                                          failureMechanism.Contribution,
-                                         hydraulicBoundaryDatabaseFilePath);
+                                         hydraulicBoundaryDatabaseFilePath,
+                                         assessmentSection.HydraulicBoundaryDatabase.EffectivePreprocessorDirectory());
         }
 
         protected override void OnCancel()
Index: Ringtoets/StabilityPointStructures/test/Ringtoets.StabilityPointStructures.Service.Test/StabilityPointStructuresCalculationServiceTest.cs
===================================================================
diff -u -r3b5e1adef92f7ce3cf8d896ec310e9203f0e8d7d -rcdc1bc16334dad7a675276648c42ac6fab5ffdfb
--- Ringtoets/StabilityPointStructures/test/Ringtoets.StabilityPointStructures.Service.Test/StabilityPointStructuresCalculationServiceTest.cs	(.../StabilityPointStructuresCalculationServiceTest.cs)	(revision 3b5e1adef92f7ce3cf8d896ec310e9203f0e8d7d)
+++ Ringtoets/StabilityPointStructures/test/Ringtoets.StabilityPointStructures.Service.Test/StabilityPointStructuresCalculationServiceTest.cs	(.../StabilityPointStructuresCalculationServiceTest.cs)	(revision cdc1bc16334dad7a675276648c42ac6fab5ffdfb)
@@ -50,6 +50,7 @@
     {
         private static readonly string testDataPath = TestHelper.GetTestDataPath(TestDataPath.Ringtoets.Integration.Service, "HydraRingCalculation");
         private static readonly string validFilePath = Path.Combine(testDataPath, "HRD dutch coast south.sqlite");
+        private static readonly string preprocessorDirectory = Path.Combine(testDataPath, "Preprocessor");
 
         [Test]
         public void Constructor_ExpectedValues()
@@ -571,7 +572,8 @@
                                                             failureMechanism.GeneralInput.N,
                                                             assessmentSection.FailureMechanismContribution.Norm,
                                                             failureMechanism.Contribution,
-                                                            validFilePath);
+                                                            validFilePath,
+                                                            preprocessorDirectory);
 
                 // Assert
                 const string expectedMessage = "The value of argument 'structureInput' (100) is invalid for Enum type 'StabilityPointStructureInflowModelType'.";
@@ -620,7 +622,8 @@
                                                             failureMechanism.GeneralInput.N,
                                                             assessmentSection.FailureMechanismContribution.Norm,
                                                             failureMechanism.Contribution,
-                                                            validFilePath);
+                                                            validFilePath,
+                                                            preprocessorDirectory);
 
                 // Assert
                 const string expectedMessage = "The value of argument 'structureInput' (100) is invalid for Enum type 'LoadSchematizationType'.";
@@ -645,7 +648,7 @@
 
             var calculator = new TestStructuresCalculator<StructuresStabilityPointCalculationInput>();
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -672,7 +675,8 @@
                                                                            failureMechanism.GeneralInput.N,
                                                                            assessmentSection.FailureMechanismContribution.Norm,
                                                                            failureMechanism.Contribution,
-                                                                           validFilePath);
+                                                                           validFilePath,
+                                                                           preprocessorDirectory);
 
                 // Assert
                 StructuresStabilityPointCalculationInput[] calculationInputs = calculator.ReceivedInputs.ToArray();
@@ -766,7 +770,7 @@
 
             var calculator = new TestStructuresCalculator<StructuresStabilityPointCalculationInput>();
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -793,7 +797,8 @@
                                                                            failureMechanism.GeneralInput.N,
                                                                            assessmentSection.FailureMechanismContribution.Norm,
                                                                            failureMechanism.Contribution,
-                                                                           validFilePath);
+                                                                           validFilePath,
+                                                                           preprocessorDirectory);
 
                 // Assert
                 StructuresStabilityPointCalculationInput[] calculationInputs = calculator.ReceivedInputs.ToArray();
@@ -887,7 +892,7 @@
 
             var calculator = new TestStructuresCalculator<StructuresStabilityPointCalculationInput>();
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -914,7 +919,8 @@
                                                                            failureMechanism.GeneralInput.N,
                                                                            assessmentSection.FailureMechanismContribution.Norm,
                                                                            failureMechanism.Contribution,
-                                                                           validFilePath);
+                                                                           validFilePath,
+                                                                           preprocessorDirectory);
 
                 // Assert
                 StructuresStabilityPointCalculationInput[] calculationInputs = calculator.ReceivedInputs.ToArray();
@@ -1008,7 +1014,7 @@
 
             var calculator = new TestStructuresCalculator<StructuresStabilityPointCalculationInput>();
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -1035,7 +1041,8 @@
                                                                            failureMechanism.GeneralInput.N,
                                                                            assessmentSection.FailureMechanismContribution.Norm,
                                                                            failureMechanism.Contribution,
-                                                                           validFilePath);
+                                                                           validFilePath,
+                                                                           preprocessorDirectory);
 
                 // Assert
                 StructuresStabilityPointCalculationInput[] calculationInputs = calculator.ReceivedInputs.ToArray();
@@ -1134,7 +1141,7 @@
             IAssessmentSection assessmentSection = AssessmentSectionHelper.CreateAssessmentSectionStub(failureMechanism, mockRepository);
 
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(new TestStructuresCalculator<StructuresStabilityPointCalculationInput>());
             mockRepository.ReplayAll();
 
@@ -1174,7 +1181,8 @@
                                                                                                failureMechanism.GeneralInput.N,
                                                                                                assessmentSection.FailureMechanismContribution.Norm,
                                                                                                failureMechanism.Contribution,
-                                                                                               validFilePath);
+                                                                                               validFilePath,
+                                                                                               preprocessorDirectory);
 
                 // Assert
                 TestHelper.AssertLogMessages(call, messages =>
@@ -1211,7 +1219,7 @@
                 EndInFailure = true
             };
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -1238,7 +1246,8 @@
                                                                                    failureMechanism.GeneralInput.N,
                                                                                    assessmentSection.FailureMechanismContribution.Norm,
                                                                                    failureMechanism.Contribution,
-                                                                                   validFilePath);
+                                                                                   validFilePath,
+                                                                                   preprocessorDirectory);
                     }
                     catch (HydraRingCalculationException)
                     {
@@ -1280,7 +1289,7 @@
                 EndInFailure = true
             };
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -1307,7 +1316,8 @@
                                                                                    failureMechanism.GeneralInput.N,
                                                                                    assessmentSection.FailureMechanismContribution.Norm,
                                                                                    failureMechanism.Contribution,
-                                                                                   validFilePath);
+                                                                                   validFilePath,
+                                                                                   preprocessorDirectory);
                     }
                     catch (HydraRingCalculationException)
                     {
@@ -1349,7 +1359,7 @@
                 LastErrorFileContent = "An error occurred"
             };
             var calculatorFactory = mockRepository.StrictMock<IHydraRingCalculatorFactory>();
-            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, string.Empty))
+            calculatorFactory.Expect(cf => cf.CreateStructuresCalculator<StructuresStabilityPointCalculationInput>(testDataPath, preprocessorDirectory))
                              .Return(calculator);
             mockRepository.ReplayAll();
 
@@ -1377,7 +1387,8 @@
                                                                                    failureMechanism.GeneralInput.N,
                                                                                    assessmentSection.FailureMechanismContribution.Norm,
                                                                                    failureMechanism.Contribution,
-                                                                                   validFilePath);
+                                                                                   validFilePath,
+                                                                                   preprocessorDirectory);
                     }
                     catch (HydraRingCalculationException e)
                     {