Index: Riskeer/Piping/src/Riskeer.Piping.Service/Probabilistic/ProbabilisticPipingCalculationService.cs
===================================================================
diff -u -r0ded44e239c0e46f08dde2696ffc6d3c81ff337c -r667edb97d13a926dd1d86d28110029995a18c9bc
--- Riskeer/Piping/src/Riskeer.Piping.Service/Probabilistic/ProbabilisticPipingCalculationService.cs	(.../ProbabilisticPipingCalculationService.cs)	(revision 0ded44e239c0e46f08dde2696ffc6d3c81ff337c)
+++ Riskeer/Piping/src/Riskeer.Piping.Service/Probabilistic/ProbabilisticPipingCalculationService.cs	(.../ProbabilisticPipingCalculationService.cs)	(revision 667edb97d13a926dd1d86d28110029995a18c9bc)
@@ -498,10 +498,15 @@
                                          PipingFailureMechanism failureMechanism,
                                          IAssessmentSection assessmentSection)
         {
-            string[] messages = ValidateHydraulicBoundaryDatabase(assessmentSection).ToArray();
+            string[] messages = ValidateHydraulicBoundaryLocation(calculation.InputParameters.HydraulicBoundaryLocation).ToArray();
 
             if (messages.Length == 0)
             {
+                messages = ValidateHydraulicBoundaryDatabase(assessmentSection, calculation.InputParameters.HydraulicBoundaryLocation).ToArray();
+            }
+
+            if (messages.Length == 0)
+            {
                 messages = ValidateFailureMechanismHasSections(failureMechanism).ToArray();
             }
 
@@ -524,9 +529,19 @@
             return false;
         }
 
-        private static IEnumerable<string> ValidateHydraulicBoundaryDatabase(IAssessmentSection assessmentSection)
+        private static IEnumerable<string> ValidateHydraulicBoundaryLocation(HydraulicBoundaryLocation hydraulicBoundaryLocation)
         {
-            string connectionValidationProblem = HydraulicBoundaryDataConnectionValidator.Validate(assessmentSection.HydraulicBoundaryData);
+            if (hydraulicBoundaryLocation == null)
+            {
+                yield return RiskeerCommonServiceResources.CalculationService_ValidateInput_No_hydraulic_boundary_location_selected;
+            }
+        }
+
+        private static IEnumerable<string> ValidateHydraulicBoundaryDatabase(IAssessmentSection assessmentSection, HydraulicBoundaryLocation hydraulicBoundaryLocation)
+        {
+            string connectionValidationProblem = HydraulicBoundaryDataConnectionValidator.Validate(
+                assessmentSection.HydraulicBoundaryData, hydraulicBoundaryLocation);
+
             if (!string.IsNullOrEmpty(connectionValidationProblem))
             {
                 yield return connectionValidationProblem;
@@ -545,11 +560,6 @@
         {
             var validationResults = new List<string>();
 
-            if (input.HydraulicBoundaryLocation == null)
-            {
-                validationResults.Add(RiskeerCommonServiceResources.CalculationService_ValidateInput_No_hydraulic_boundary_location_selected);
-            }
-
             validationResults.AddRange(PipingCalculationValidationHelper.GetValidationErrors(input));
 
             if (!validationResults.Any())