Index: Ringtoets/AssemblyTool/src/Ringtoets.AssemblyTool.KernelWrapper/Creators/FailureMechanismSectionAssemblyCreator.cs
===================================================================
diff -u -r793c364533afbb491a1189d89ed424e0a4729218 -rc3624dc5582de7ad3c87ad9e536c551f7c5e8c43
--- Ringtoets/AssemblyTool/src/Ringtoets.AssemblyTool.KernelWrapper/Creators/FailureMechanismSectionAssemblyCreator.cs	(.../FailureMechanismSectionAssemblyCreator.cs)	(revision 793c364533afbb491a1189d89ed424e0a4729218)
+++ Ringtoets/AssemblyTool/src/Ringtoets.AssemblyTool.KernelWrapper/Creators/FailureMechanismSectionAssemblyCreator.cs	(.../FailureMechanismSectionAssemblyCreator.cs)	(revision c3624dc5582de7ad3c87ad9e536c551f7c5e8c43)
@@ -49,12 +49,7 @@
                 throw new ArgumentNullException(nameof(result));
             }
 
-            if (!result.FailureProbability.HasValue)
-            {
-                throw new ArgumentException("The failure probability of the result may not be null.");
-            }
-
-            return new FailureMechanismSectionAssembly(result.FailureProbability.Value,
+            return new FailureMechanismSectionAssembly(result.FailureProbability ?? double.NaN,
                                                        ConvertFailureMechanismSectionCategory(result.Result));
         }