Index: Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.IO/Importers/RingtoetsMacroStabilityInwardsSurfaceLineExtensions.cs
===================================================================
diff -u -r683ff9234262d9fa3bea5edc0abe35254f80e49d -rf5856404ce0793d444cd6dc88ab0aef9922ad39e
--- Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.IO/Importers/RingtoetsMacroStabilityInwardsSurfaceLineExtensions.cs	(.../RingtoetsMacroStabilityInwardsSurfaceLineExtensions.cs)	(revision 683ff9234262d9fa3bea5edc0abe35254f80e49d)
+++ Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.IO/Importers/RingtoetsMacroStabilityInwardsSurfaceLineExtensions.cs	(.../RingtoetsMacroStabilityInwardsSurfaceLineExtensions.cs)	(revision f5856404ce0793d444cd6dc88ab0aef9922ad39e)
@@ -53,7 +53,7 @@
             }
             if (characteristicPoints == null)
             {
-                return;
+                throw new SurfaceLineTransformException($"Karakteristieke punten definitie voor profielschematisatie '{surfaceLine.Name}' is verplicht.");
             }
 
             surfaceLine.TrySetSurfaceLevelOutside(characteristicPoints.SurfaceLevelOutside);