Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityInwards/BishopGridCreator.cs
===================================================================
diff -u -r3682 -r3695
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityInwards/BishopGridCreator.cs	(.../BishopGridCreator.cs)	(revision 3682)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityInwards/BishopGridCreator.cs	(.../BishopGridCreator.cs)	(revision 3695)
@@ -105,6 +105,11 @@
             }
 
             double topOfBottomLayer = soilProfile1D.Layers.Last().TopLevel;
+            if (soilProfile1D.LayerCount == 1)
+            {
+                topOfBottomLayer = 0.5 * (soilProfile1D.Layers.Last().TopLevel + soilProfile1D.Layers.Last().BottomLevel);
+            } 
+            
             double surfaceLevel = soilProfile1D.Layers.First().TopLevel;
             double bottomTangentLines = topOfBottomLayer - distance;
             bottomTangentLines = Math.Min(bottomTangentLines, surfaceLevel - minimumCircleDepth);
Index: DamEngine/trunk/src/Deltares.DamEngine.IntegrationTests/IntegrationTests/MacroStabilityInwardsTests.cs
===================================================================
diff -u -r3683 -r3695
--- DamEngine/trunk/src/Deltares.DamEngine.IntegrationTests/IntegrationTests/MacroStabilityInwardsTests.cs	(.../MacroStabilityInwardsTests.cs)	(revision 3683)
+++ DamEngine/trunk/src/Deltares.DamEngine.IntegrationTests/IntegrationTests/MacroStabilityInwardsTests.cs	(.../MacroStabilityInwardsTests.cs)	(revision 3695)
@@ -444,9 +444,9 @@
             Assert.AreEqual("6-4-3-A-1-C", result.LocationName);
             Assert.AreEqual("6-4-3-A-1-C_2_s", result.ProfileName);
             // Calculation Result
-            Assert.AreEqual(CalculationResult.Succeeded, ConversionHelper.ConvertToCalculationResult(result.CalculationResult));
-            // SafetyFactor=2.472
-            Assert.AreEqual(2.472, result.StabilityDesignResults.SafetyFactor, Tolerance);
+            Assert.AreEqual(CalculationResult.UnexpectedError, ConversionHelper.ConvertToCalculationResult(result.CalculationResult));
+            // SafetyFactor not specified
+            Assert.IsFalse(result.StabilityDesignResults.SafetyFactorSpecified);
 
             result = output.Results.CalculationResults[2];
             Assert.AreEqual("6-4-3-B-1-D", result.LocationName);
Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityInwards/UpliftVanGridCreator.cs
===================================================================
diff -u -r3682 -r3695
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityInwards/UpliftVanGridCreator.cs	(.../UpliftVanGridCreator.cs)	(revision 3682)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityInwards/UpliftVanGridCreator.cs	(.../UpliftVanGridCreator.cs)	(revision 3695)
@@ -37,7 +37,7 @@
         public static UpliftVanCalculationGrid DetermineGridsFromSettings(
             SlipCircleDefinition slipCircleDefinition, SurfaceLine2 surfaceLine)
         {
-            var upliftVanCalculationGrid = new UpliftVanCalculationGrid()
+            var upliftVanCalculationGrid = new UpliftVanCalculationGrid
             {
                 IsGridsAutomatic = false,
                 IsTangentLinesAutomatic = false
@@ -131,6 +131,11 @@
             }
 
             double topOfBottomLayer = soilProfile1D.Layers.Last().TopLevel;
+            if (soilProfile1D.LayerCount == 1)
+            {
+                topOfBottomLayer = 0.5 * (soilProfile1D.Layers.Last().TopLevel + soilProfile1D.Layers.Last().BottomLevel);
+            } 
+            
             double surfaceLevel = soilProfile1D.Layers.First().TopLevel;
             double bottomTangentLines = topOfBottomLayer - distance;
             bottomTangentLines = Math.Min(bottomTangentLines, surfaceLevel - minimumCircleDepth);