Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/PlLinesToWaternetConverter.cs
===================================================================
diff -u -r5027 -r5033
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/PlLinesToWaternetConverter.cs	(.../PlLinesToWaternetConverter.cs)	(revision 5027)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/PlLinesToWaternetConverter.cs	(.../PlLinesToWaternetConverter.cs)	(revision 5033)
@@ -279,6 +279,10 @@
                 waternetLineBottom.Name = waternetLine4BottomName + " (" + (i + 1) + ")";
                 waternet.WaternetLineList.Add(waternetLineBottom);
             }
+            else
+            {
+                throw new NoNullAllowedException(string.Format(Resources.PlLinesToWaternetConverter_ErrorDuringDeterminationCoordinatesInBetweenAquifer, soilProfile.Name));
+            }
         }
     }
 
Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/Properties/Resources.Designer.cs
===================================================================
diff -u -r4982 -r5033
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 4982)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 5033)
@@ -349,6 +349,15 @@
         }
         
         /// <summary>
+        /// Looks up a localized string similar to An unexpected error occured during the determination of the top and bottom boundaries of the in-between aquifer layer.
+        /// </summary>
+        internal static string PlLinesToWaternetConverter_ErrorDuringDeterminationCoordinatesInBetweenAquifer {
+            get {
+                return ResourceManager.GetString("PlLinesToWaternetConverter_ErrorDuringDeterminationCoordinatesInBetweenAquifer", resourceCulture);
+            }
+        }
+        
+        /// <summary>
         ///   Looks up a localized string similar to Adapting the slope of the dike failed. Probably the slope is too steep or too shallow..
         /// </summary>
         internal static string SlopeErrorNoIntersection {
Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/Properties/Resources.resx
===================================================================
diff -u -r4982 -r5033
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/Properties/Resources.resx	(.../Resources.resx)	(revision 4982)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/Properties/Resources.resx	(.../Resources.resx)	(revision 5033)
@@ -277,6 +277,9 @@
     <data name="PlLinesToWaternetConverter_NoSurfaceLineDefined" xml:space="preserve">
     <value>No surface line object defined</value>
   </data>
+    <data name="PlLinesToWaternetConverter_ErrorDuringDeterminationCoordinatesInBetweenAquifer" xml:space="preserve">
+    <value>An unexpected error occured during the determination of the top and bottom boundaries of the in-between aquifer layer.</value>      
+  </data>
     <data name="DesignCalculatorNoSegmentsWithFailureMechanismTypePresent" xml:space="preserve">
     <value>No segments with failure mechanism {0} present</value>
   </data>
Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/Properties/Resources.nl-NL.resx
===================================================================
diff -u -r4982 -r5033
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/Properties/Resources.nl-NL.resx	(.../Resources.nl-NL.resx)	(revision 4982)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/Properties/Resources.nl-NL.resx	(.../Resources.nl-NL.resx)	(revision 5033)
@@ -273,6 +273,9 @@
     <data name="PlLinesToWaternetConverter_NoSurfaceLineDefined" xml:space="preserve">
     <value>Geen object voor maaiveld gedefinieerd</value>
   </data>
+    <data name="PlLinesToWaternetConverter_ErrorDuringDeterminationCoordinatesInBetweenAquifer" xml:space="preserve">
+    <value>Er is een onverwachte fout opgetreden bij het bepalen van de boven- en ondergrenzen van de tussenliggende watervoerende laag.</value>  
+  </data>
     <data name="DesignCalculatorNoSegmentsWithFailureMechanismTypePresent" xml:space="preserve">
     <value>Geen segmenten met faalmechanisme {0} aanwezig</value>
   </data>