Index: Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Forms/Views/HeightStructuresScenariosView.cs
===================================================================
diff -u -rfcad48d7beb394e1ac15cfe4289a7381e05aa883 -r83ac738ad69ef53eba6ca4f647657e5b7f024b96
--- Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Forms/Views/HeightStructuresScenariosView.cs	(.../HeightStructuresScenariosView.cs)	(revision fcad48d7beb394e1ac15cfe4289a7381e05aa883)
+++ Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Forms/Views/HeightStructuresScenariosView.cs	(.../HeightStructuresScenariosView.cs)	(revision 83ac738ad69ef53eba6ca4f647657e5b7f024b96)
@@ -58,7 +58,7 @@
             calculationInputObserver = new RecursiveObserver<CalculationGroup, ICalculationInput>(
                 UpdateDataGridViewDataSource, cg => cg.Children.Concat<object>(cg.Children
                                                                                  .OfType<StructuresCalculation<HeightStructuresInput>>()
-                                                                                 .Select(c => c.InputParameters)));
+                                                                                 .Select(c => c.InputParameters)).ToArray());
             calculationGroupObserver = new RecursiveObserver<CalculationGroup, ICalculationBase>(UpdateDataGridViewDataSource, c => c.Children);
         }