Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/PresentationObjects/PipingCalculationGroupContext.cs
===================================================================
diff -u -r40b1fa451f977a22d49c8bc37d68c8dd047262e1 -r2b26a2f9062fe2221ffdb670496c80bc36ba0cfb
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/PresentationObjects/PipingCalculationGroupContext.cs	(.../PipingCalculationGroupContext.cs)	(revision 40b1fa451f977a22d49c8bc37d68c8dd047262e1)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/PresentationObjects/PipingCalculationGroupContext.cs	(.../PipingCalculationGroupContext.cs)	(revision 2b26a2f9062fe2221ffdb670496c80bc36ba0cfb)
@@ -50,6 +50,12 @@
                                             Resources.PipingContext_DataDescription_PipingFailureMechanism);
                 throw new ArgumentNullException("pipingFailureMechanism", message);
             }
+            if (assessmentSection == null)
+            {
+                var message = String.Format(Resources.PipingContext_AssertInputsAreNotNull_DataDescription_0_cannot_be_null,
+                                            Resources.PipingContext_DataDescription_AssessmentSection);
+                throw new ArgumentNullException("assessmentSection", message);
+            }
 
             PipingFailureMechanism = pipingFailureMechanism;