Index: Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Data/ClosingStructuresInput.cs
===================================================================
diff -u -r13e66da0fff74d0062fe1c0872691a6634a4853b -r88e625c7d47b0efd2a5ea8ea118e524c8f8e36ca
--- Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Data/ClosingStructuresInput.cs	(.../ClosingStructuresInput.cs)	(revision 13e66da0fff74d0062fe1c0872691a6634a4853b)
+++ Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Data/ClosingStructuresInput.cs	(.../ClosingStructuresInput.cs)	(revision 88e625c7d47b0efd2a5ea8ea118e524c8f8e36ca)
@@ -362,7 +362,7 @@
             set
             {
                 RoundedDouble newOrientationValue = value.ToPrecision(structureNormalOrientation.NumberOfDecimalPlaces);
-                if (newOrientationValue < 0 || newOrientationValue > 360)
+                if (double.IsNaN(newOrientationValue) || newOrientationValue < 0 || newOrientationValue > 360)
                 {
                     throw new ArgumentOutOfRangeException("value", RingtoetsCommonDataResources.Orientation_Value_needs_to_be_between_0_and_360);
                 }