Index: Ringtoets/Common/src/Ringtoets.Common.Forms/Views/FailureMechanismResultView.cs
===================================================================
diff -u -r23a37b025a5d0358c1f30fb31de41a2c284519a5 -rf5e1194ee412e86277cee388a75c39db189f2b3e
--- Ringtoets/Common/src/Ringtoets.Common.Forms/Views/FailureMechanismResultView.cs	(.../FailureMechanismResultView.cs)	(revision 23a37b025a5d0358c1f30fb31de41a2c284519a5)
+++ Ringtoets/Common/src/Ringtoets.Common.Forms/Views/FailureMechanismResultView.cs	(.../FailureMechanismResultView.cs)	(revision f5e1194ee412e86277cee388a75c39db189f2b3e)
@@ -63,7 +63,7 @@
             failureMechanismObserver = new Observer(UpdataDataGridViewDataSource);
             failureMechanismSectionResultObserver = new RecursiveObserver<IFailureMechanism, FailureMechanismSectionResult>(RefreshDataGridView, mechanism => mechanism.SectionResults);
             // The concat is needed to observe the input of calculations in child groups.
-            calculationInputObserver = new RecursiveObserver<ICalculationGroup, ICalculationInput>(UpdataDataGridViewDataSource, cg => cg.Children.Concat<object>(cg.Children.OfType<ICalculationScenario>().Select(c => c.Input)));
+            calculationInputObserver = new RecursiveObserver<ICalculationGroup, ICalculationInput>(UpdataDataGridViewDataSource, cg => cg.Children.Concat<object>(cg.Children.OfType<ICalculationScenario>().Select(c => c.GetObservableInput())));
             calculationGroupObserver = new RecursiveObserver<ICalculationGroup, ICalculationBase>(UpdataDataGridViewDataSource, c => c.Children);
             Load += OnLoad;
         }
@@ -83,8 +83,12 @@
 
                 failureMechanismObserver.Observable = failureMechanism;
                 failureMechanismSectionResultObserver.Observable = failureMechanism;
-                calculationInputObserver.Observable = failureMechanism != null ? failureMechanism.CalculationsGroup : null;
-                calculationGroupObserver.Observable = failureMechanism != null ? failureMechanism.CalculationsGroup : null;
+
+                var calculatableFailureMechanism = failureMechanism as ICalculatableFailureMechanism;
+                CalculationGroup observableGroup = calculatableFailureMechanism != null ? calculatableFailureMechanism.CalculationsGroup : null;
+
+                calculationInputObserver.Observable = observableGroup;
+                calculationGroupObserver.Observable = observableGroup;
             }
         }