Index: dam engine/trunk/src/Deltares.DamEngine.Calculators/Dikes Design/DesignCalculator.cs
===================================================================
diff -u -r638 -r649
--- dam engine/trunk/src/Deltares.DamEngine.Calculators/Dikes Design/DesignCalculator.cs	(.../DesignCalculator.cs)	(revision 638)
+++ dam engine/trunk/src/Deltares.DamEngine.Calculators/Dikes Design/DesignCalculator.cs	(.../DesignCalculator.cs)	(revision 649)
@@ -46,15 +46,20 @@
                         damKernelInput.DesignScenario = location.Scenarios[designScenarioIndex];
                         IKernelDataInput kernelDataInput = kernelWrapper.Prepare(damKernelInput);
 
-                        // Perform calculation
-                        List<LogMessage> locationCalculationMessages;
-                        IKernelDataOutput kernelDataOutput = kernelWrapper.Execute(kernelDataInput, out locationCalculationMessages);
-                        calculationMessages.AddRange(locationCalculationMessages);
+                        // Sometimes the kernelDataInput is not created (p.e when soilprofileprobablility is meant for 
+                        // stability where Piping calc is wanted). In that case, do nothing but just skip.
+                        if (kernelDataInput != null)
+                        {
+                            // Perform calculation
+                            List<LogMessage> locationCalculationMessages;
+                            IKernelDataOutput kernelDataOutput = kernelWrapper.Execute(kernelDataInput, out locationCalculationMessages);
+                            calculationMessages.AddRange(locationCalculationMessages);
 
-                        // Process output
-                        DesignResult designResult;
-                        kernelWrapper.PostProcess(damKernelInput, kernelDataOutput, out designResult);
-                        damProjectData.DesignCalculations.Add(designResult);
+                            // Process output
+                            DesignResult designResult;
+                            kernelWrapper.PostProcess(damKernelInput, kernelDataOutput, out designResult);
+                            damProjectData.DesignCalculations.Add(designResult);
+                        }
                     }
                 }
             }