Index: Ringtoets/Common/src/Ringtoets.Common.Service/Structures/StructuresCalculationServiceBase.cs
===================================================================
diff -u -rf8c28b3b04cdabb62ea37772efcb1f4ebbbf2b9e -r9cf89e3f60d17b61c5ef1ba1c4c7e18ca0c9b2f4
--- Ringtoets/Common/src/Ringtoets.Common.Service/Structures/StructuresCalculationServiceBase.cs	(.../StructuresCalculationServiceBase.cs)	(revision f8c28b3b04cdabb62ea37772efcb1f4ebbbf2b9e)
+++ Ringtoets/Common/src/Ringtoets.Common.Service/Structures/StructuresCalculationServiceBase.cs	(.../StructuresCalculationServiceBase.cs)	(revision 9cf89e3f60d17b61c5ef1ba1c4c7e18ca0c9b2f4)
@@ -339,13 +339,15 @@
         {
             var validationResults = new List<string>();
 
-            string databaseFilePathValidationProblem = HydraulicBoundaryDatabaseHelper.ValidatePathForCalculation(assessmentSection.HydraulicBoundaryDatabase.FilePath);
+            string preprocessorDirectory = assessmentSection.HydraulicBoundaryDatabase.EffectivePreprocessorDirectory();
+            string databaseFilePathValidationProblem = HydraulicBoundaryDatabaseHelper.ValidatePathForCalculation(assessmentSection.HydraulicBoundaryDatabase.FilePath,
+                                                                                                                  preprocessorDirectory);
             if (!string.IsNullOrEmpty(databaseFilePathValidationProblem))
             {
                 validationResults.Add(databaseFilePathValidationProblem);
             }
 
-            string preprocessorDirectoryValidationProblem = HydraulicBoundaryDatabaseHelper.ValidatePreprocessorDirectory(assessmentSection.HydraulicBoundaryDatabase.EffectivePreprocessorDirectory());
+            string preprocessorDirectoryValidationProblem = HydraulicBoundaryDatabaseHelper.ValidatePreprocessorDirectory(preprocessorDirectory);
             if (!string.IsNullOrEmpty(preprocessorDirectoryValidationProblem))
             {
                 validationResults.Add(preprocessorDirectoryValidationProblem);