Index: Ringtoets/DuneErosion/src/Ringtoets.DuneErosion.Plugin/DuneErosionPlugin.cs
===================================================================
diff -u -r1cd44b288670cb25c0701916ffb47b0de3cb4974 -r3f33a67c2e73865c56f405756b30d73d8cb1862e
--- Ringtoets/DuneErosion/src/Ringtoets.DuneErosion.Plugin/DuneErosionPlugin.cs	(.../DuneErosionPlugin.cs)	(revision 1cd44b288670cb25c0701916ffb47b0de3cb4974)
+++ Ringtoets/DuneErosion/src/Ringtoets.DuneErosion.Plugin/DuneErosionPlugin.cs	(.../DuneErosionPlugin.cs)	(revision 3f33a67c2e73865c56f405756b30d73d8cb1862e)
@@ -131,8 +131,8 @@
                 GetViewData = context => context.WrappedData,
                 CloseForData = CloseDuneLocationsViewForData,
                 CreateInstance = context => new DuneLocationCalculationsView(context.WrappedData,
-                                                                  context.FailureMechanism,
-                                                                  context.AssessmentSection),
+                                                                             context.FailureMechanism,
+                                                                             context.AssessmentSection),
                 AfterCreate = (view, context) => { view.CalculationGuiService = duneLocationCalculationGuiService; },
                 AdditionalDataCheck = context => context.WrappedData.Any()
             };
@@ -246,14 +246,16 @@
 
         #region DuneLocationsContext TreeNodeInfo
 
-        private static string ValidateAllDataAvailableAndGetErrorMessage(IAssessmentSection assessmentSection, DuneErosionFailureMechanism failureMechanism)
+        private static string ValidateAllDataAvailableAndGetErrorMessage(IAssessmentSection assessmentSection,
+                                                                         double failureMechanismContribution,
+                                                                         IEnumerable<DuneLocationCalculation> calculations)
         {
-            if (failureMechanism.Contribution <= 0.0)
+            if (failureMechanismContribution <= 0.0)
             {
                 return RingtoetsCommonFormsResources.Contribution_of_failure_mechanism_zero;
             }
 
-            if (!failureMechanism.DuneLocations.Any())
+            if (!calculations.Any())
             {
                 return Resources.DuneErosionPlugin_DuneLocationsContextMenuStrip_Calculate_all_ToolTip_no_locations;
             }
@@ -280,7 +282,9 @@
                                                                 context.FailureMechanism.GetMechanismSpecificNorm(context.AssessmentSection.FailureMechanismContribution.Norm));
                 });
 
-            string validationText = ValidateAllDataAvailableAndGetErrorMessage(context.AssessmentSection, context.FailureMechanism);
+            string validationText = ValidateAllDataAvailableAndGetErrorMessage(context.AssessmentSection,
+                                                                               context.FailureMechanism.Contribution,
+                                                                               context.WrappedData);
             if (!string.IsNullOrEmpty(validationText))
             {
                 calculateAllItem.Enabled = false;
Index: Ringtoets/DuneErosion/test/Ringtoets.DuneErosion.Plugin.Test/TreeNodeInfos/DuneLocationCalculationsContextTreeNodeInfoTest.cs
===================================================================
diff -u -rd02138fd08881584c9ec57b6d87f6426c6e43eb2 -r3f33a67c2e73865c56f405756b30d73d8cb1862e
--- Ringtoets/DuneErosion/test/Ringtoets.DuneErosion.Plugin.Test/TreeNodeInfos/DuneLocationCalculationsContextTreeNodeInfoTest.cs	(.../DuneLocationCalculationsContextTreeNodeInfoTest.cs)	(revision d02138fd08881584c9ec57b6d87f6426c6e43eb2)
+++ Ringtoets/DuneErosion/test/Ringtoets.DuneErosion.Plugin.Test/TreeNodeInfos/DuneLocationCalculationsContextTreeNodeInfoTest.cs	(.../DuneLocationCalculationsContextTreeNodeInfoTest.cs)	(revision 3f33a67c2e73865c56f405756b30d73d8cb1862e)
@@ -227,20 +227,22 @@
                     Contribution = 10
                 };
 
-                var builder = new CustomItemsOnlyContextMenuBuilder();
-                var context = new DuneLocationCalculationsContext(new ObservableList<DuneLocationCalculation>(),
+                var duneLocationCalculations = new ObservableList<DuneLocationCalculation>
+                {
+                    new DuneLocationCalculation(new TestDuneLocation())
+                };
+                var context = new DuneLocationCalculationsContext(duneLocationCalculations,
                                                                   failureMechanism,
                                                                   assessmentSection);
 
+                var builder = new CustomItemsOnlyContextMenuBuilder();
                 var gui = mocks.Stub<IGui>();
                 gui.Stub(cmp => cmp.Get(context, treeViewControl)).Return(builder);
 
                 mocks.ReplayAll();
 
                 plugin.Gui = gui;
 
-                failureMechanism.DuneLocations.Add(new TestDuneLocation());
-
                 // Call
                 using (ContextMenuStrip menu = info.ContextMenuStrip(context, null, treeViewControl))
                 {
@@ -367,20 +369,22 @@
                     Contribution = 10
                 };
 
-                var builder = new CustomItemsOnlyContextMenuBuilder();
-                var context = new DuneLocationCalculationsContext(new ObservableList<DuneLocationCalculation>(),
+                var duneLocationCalculations = new ObservableList<DuneLocationCalculation>
+                {
+                    new DuneLocationCalculation(new TestDuneLocation())
+                };
+                var context = new DuneLocationCalculationsContext(duneLocationCalculations,
                                                                   failureMechanism,
                                                                   assessmentSection);
 
+                var builder = new CustomItemsOnlyContextMenuBuilder();
                 var gui = mocks.Stub<IGui>();
                 gui.Stub(cmp => cmp.Get(context, treeViewControl)).Return(builder);
 
                 mocks.ReplayAll();
 
                 plugin.Gui = gui;
 
-                failureMechanism.DuneLocations.Add(new TestDuneLocation());
-
                 // Call
                 using (ContextMenuStrip menu = info.ContextMenuStrip(context, null, treeViewControl))
                 {
@@ -448,20 +452,20 @@
                 var gui = mocks.Stub<IGui>();
                 gui.Stub(cmp => cmp.Get(context, treeViewControl)).Return(builder);
                 gui.Stub(g => g.MainWindow).Return(mainWindow);
-                var locationObserver = mocks.StrictMock<IObserver>();
-                locationObserver.Expect(o => o.UpdateObserver()).Repeat.Times(failureMechanism.DuneLocations.Count);
-                var locationsObsever = mocks.StrictMock<IObserver>();
+                var calculationObserver = mocks.StrictMock<IObserver>();
+                calculationObserver.Expect(o => o.UpdateObserver()).Repeat.Times(duneLocationCalculations.Count);
+                var calculationsObserver = mocks.StrictMock<IObserver>();
 
-                int nrOfCalculators = failureMechanism.DuneLocations.Count;
+                int nrOfCalculators = duneLocationCalculations.Count;
                 var calculatorFactory = mocks.Stub<IHydraRingCalculatorFactory>();
                 calculatorFactory.Expect(cf => cf.CreateDunesBoundaryConditionsCalculator(testDataPath, string.Empty))
                                  .Return(new TestDunesBoundaryConditionsCalculator())
                                  .Repeat
                                  .Times(nrOfCalculators);
                 mocks.ReplayAll();
 
-                failureMechanism.DuneLocations.Attach(locationsObsever);
-                failureMechanism.DuneLocations.ForEachElementDo(location => location.Attach(locationObserver));
+                duneLocationCalculations.Attach(calculationsObserver);
+                duneLocationCalculations.ForEachElementDo(location => location.Attach(calculationObserver));
 
                 plugin.Gui = gui;
                 plugin.Activate();