Index: DamEngine/trunk/src/Deltares.DamEngine.Data/Geotechnics/SoilLayer1D.cs
===================================================================
diff -u -r4540 -r5028
--- DamEngine/trunk/src/Deltares.DamEngine.Data/Geotechnics/SoilLayer1D.cs	(.../SoilLayer1D.cs)	(revision 4540)
+++ DamEngine/trunk/src/Deltares.DamEngine.Data/Geotechnics/SoilLayer1D.cs	(.../SoilLayer1D.cs)	(revision 5028)
@@ -95,7 +95,11 @@
             // don't do anything if bottom is already value
             if (Math.Abs(value - BottomLevel) > GeometryConstants.Accuracy)
             {
-                SoilLayer1D layerBelow = LayerBelow();
+                SoilLayer1D layerBelow = null;
+                if (SoilProfile != null)
+                {
+                    layerBelow = LayerBelow();
+                }
                 if (layerBelow != null)
                 {
                     layerBelow.topLevel = value;