Index: Ringtoets/Common/src/Ringtoets.Common.Util/AssignUnassignCalculations.cs
===================================================================
diff -u -r5dabca97fffab41012aafa58da5bc4cd0192e947 -r83ac738ad69ef53eba6ca4f647657e5b7f024b96
--- Ringtoets/Common/src/Ringtoets.Common.Util/AssignUnassignCalculations.cs	(.../AssignUnassignCalculations.cs)	(revision 5dabca97fffab41012aafa58da5bc4cd0192e947)
+++ Ringtoets/Common/src/Ringtoets.Common.Util/AssignUnassignCalculations.cs	(.../AssignUnassignCalculations.cs)	(revision 83ac738ad69ef53eba6ca4f647657e5b7f024b96)
@@ -55,7 +55,7 @@
             SectionResultWithCalculationAssignment[] sectionResultsArray = sectionResults.ToArray();
 
             IDictionary<string, List<ICalculation>> calculationsPerSegmentName =
-                CollectCalculationsPerSection(sectionResultsArray.Select(sr => sr.Result.Section), calculations);
+                CollectCalculationsPerSection(sectionResultsArray.Select(sr => sr.Result.Section).ToArray(), calculations);
 
             return UnassignCalculationInAllSectionResultsAndAssignSingleRemainingCalculation(
                 sectionResultsArray,