Index: DamClients/DamUI/trunk/src/Dam/Tests/DamEngineIo/FillXmlInputFromDamUiTests.cs
===================================================================
diff -u -r2527 -r2612
--- DamClients/DamUI/trunk/src/Dam/Tests/DamEngineIo/FillXmlInputFromDamUiTests.cs	(.../FillXmlInputFromDamUiTests.cs)	(revision 2527)
+++ DamClients/DamUI/trunk/src/Dam/Tests/DamEngineIo/FillXmlInputFromDamUiTests.cs	(.../FillXmlInputFromDamUiTests.cs)	(revision 2612)
@@ -85,6 +85,8 @@
             CompareDamProjectData(actualDamProjectData, expectedDamProjectData);
         }
 
+        #region CreateTestData
+
         private DamProjectData CreateExampleDamProjectData()
         {
             var damProjectData = new DamProjectData();
@@ -415,6 +417,7 @@
             designScenario.RequiredSafetyFactorPiping = 1.0 * factor + 0.66;
             return designScenario;
         }
+
         private List<SurfaceLine2> CreateSurfaceLines()
         {
             var surfaceLines = new List<SurfaceLine2>();
@@ -441,6 +444,7 @@
             AddPointToSurfaceLine(surfaceLine, 18.0, 1.0, CharacteristicPointType.DikeToeAtPolder);
             AddPointToSurfaceLine(surfaceLine, 24.0, 1.0, CharacteristicPointType.SurfaceLevelInside);
         }
+
         private void AddPointToSurfaceLine(SurfaceLine2 surfaceLine, double xCoordinate, double zCoordinate, CharacteristicPointType characteristicPointType)
         {
             var geometryPoint = new GeometryPoint()
@@ -485,6 +489,7 @@
                 dike.SoilProfiles.Add(profile);
             }
         }
+
         private static void FillSegments(DamProjectData damProjectData)
         {
             var segmentCount = 2;
@@ -513,6 +518,9 @@
                 damProjectData.WaterBoard.Segments.Add(segment);
             }
         }
+        
+        #endregion CreateTestData
+
         [Test]
         [TestCase("location_12_2_1D1")] // Between "location_12" and "_2_1D1" there are 2 illegal characters (1F hex)
         [ExpectedException(typeof(IdValidatorException), ExpectedMessage = "Location has an invalid name location_12_2_1D1")]
@@ -601,21 +609,98 @@
         [ExpectedException(typeof(NullReferenceException), ExpectedMessage = "Location 'Location 1', scenario '1' has no river level")]
         public void RaiseExceptionWhenRiverLevelIsMissing()
         {
-            // Given DataSet with undefined riverlevel
+            // Given DataSet with undefined RiverLevel
             DamProjectData expectedDamProjectData = CreateExampleDamProjectData();
             var scenario = expectedDamProjectData.WaterBoard.Dikes[0].Locations[0].Scenarios[0];
             scenario.RiverLevel = null;
 
             // When Writing Xml
-            string xmlString;
             Input input = FillXmlInputFromDamUi.CreateInput(expectedDamProjectData);
-            xmlString = DamXmlSerialization.SaveInputAsXmlString(input);
+            string xmlString = DamXmlSerialization.SaveInputAsXmlString(input);
 
             // Then Raise Exception With Clear Message()
             input = DamXmlSerialization.LoadInputFromXmlString(xmlString);
             DamProjectData actualDamProjectData = FillDamUiFromXmlInput.CreateDamProjectData(input);
             CompareDamProjectData(actualDamProjectData, expectedDamProjectData);
         }
+
+        [Test]
+        [TestCase(FailureMechanismSystemType.StabilityOutside)]
+        [ExpectedException(typeof(NullReferenceException), ExpectedMessage = "Location 'Location 1', scenario '1' has no river level low")]
+        public void RaiseExceptionWhenRiverLevelLowIsMissingForStabilityOutside(FailureMechanismSystemType failureMechanismSystemType)
+        {
+            // Given DataSet with undefined RiverLevelLow, for stability outside
+            DamProjectData expectedDamProjectData = CreateExampleDamProjectData();
+            var scenario = expectedDamProjectData.WaterBoard.Dikes[0].Locations[0].Scenarios[0];
+            scenario.RiverLevelLow = null;
+            var currentSpecification = expectedDamProjectData.DamProjectCalculationSpecification.CurrentSpecification;
+            currentSpecification.FailureMechanismSystemType = failureMechanismSystemType;
+            // First set PipingModelType to default because it will be set to default when reading the xml back when FailureMechanismSystemType is not Piping
+            currentSpecification.PipingModelType = PipingModelType.Sellmeijer4Forces;
+            // Next line sets the CalculationType to Bishop as well
+            currentSpecification.StabilityModelType = MStabModelType.Bishop;
+
+            // When Writing Xml
+            Input input = FillXmlInputFromDamUi.CreateInput(expectedDamProjectData);
+            string xmlString = DamXmlSerialization.SaveInputAsXmlString(input);
+
+            // Then Raise Exception With Clear Message()
+            input = DamXmlSerialization.LoadInputFromXmlString(xmlString);
+            DamProjectData actualDamProjectData = FillDamUiFromXmlInput.CreateDamProjectData(input);
+            CompareDamProjectData(actualDamProjectData, expectedDamProjectData);
+        }
+
+        [Test]
+        [TestCase(FailureMechanismSystemType.StabilityInside)]
+        [TestCase(FailureMechanismSystemType.HorizontalBalance)]
+        [TestCase(FailureMechanismSystemType.FlowSlide)]
+        public void DoNotRaiseExceptionWhenRiverLevelLowIsMissingForOtherTypeThanStabilityOutsideOrPiping(FailureMechanismSystemType failureMechanismSystemType)
+        {
+            // Given DataSet with undefined RiverLevelLow, for stability inside / horizontal balance / flow slide
+            DamProjectData expectedDamProjectData = CreateExampleDamProjectData();
+            var scenario = expectedDamProjectData.WaterBoard.Dikes[0].Locations[0].Scenarios[0];
+            scenario.RiverLevelLow = null;
+            var currentSpecification = expectedDamProjectData.DamProjectCalculationSpecification.CurrentSpecification;
+            currentSpecification.FailureMechanismSystemType = failureMechanismSystemType;
+            // First set PipingModelType to default because it will be set to default when reading the xml back when FailureMechanismSystemType is not Piping
+            currentSpecification.PipingModelType = PipingModelType.Sellmeijer4Forces;
+            // Next line sets the CalculationType to Bishop as well
+            currentSpecification.StabilityModelType = MStabModelType.Bishop;
+
+            // When Writing Xml
+            Input input = FillXmlInputFromDamUi.CreateInput(expectedDamProjectData);
+            string xmlString = DamXmlSerialization.SaveInputAsXmlString(input);
+
+            // Then Raise Exception With Clear Message()
+            input = DamXmlSerialization.LoadInputFromXmlString(xmlString);
+            DamProjectData actualDamProjectData = FillDamUiFromXmlInput.CreateDamProjectData(input);
+            CompareDamProjectData(actualDamProjectData, expectedDamProjectData);
+        }
+
+        [Test]
+        [TestCase(FailureMechanismSystemType.Piping)]
+        public void DoNotRaiseExceptionWhenRiverLevelLowIsMissingForPiping(FailureMechanismSystemType failureMechanismSystemType)
+        {
+            // Given DataSet with undefined RiverLevelLow, for piping
+            DamProjectData expectedDamProjectData = CreateExampleDamProjectData();
+            var scenario = expectedDamProjectData.WaterBoard.Dikes[0].Locations[0].Scenarios[0];
+            scenario.RiverLevelLow = null;
+            var currentSpecification = expectedDamProjectData.DamProjectCalculationSpecification.CurrentSpecification;
+            currentSpecification.FailureMechanismSystemType = failureMechanismSystemType;
+            // First set StabilityModelType to default because it will be set to default when reading the xml back when FailureMechanismSystemType is not Stability
+            currentSpecification.StabilityModelType = MStabModelType.Bishop;
+            // Next line sets the CalculationType to Bligh as well
+            currentSpecification.PipingModelType = PipingModelType.Bligh;
+
+            // When Writing Xml
+            Input input = FillXmlInputFromDamUi.CreateInput(expectedDamProjectData);
+            string xmlString = DamXmlSerialization.SaveInputAsXmlString(input);
+
+            // Then Raise Exception With Clear Message()
+            input = DamXmlSerialization.LoadInputFromXmlString(xmlString);
+            DamProjectData actualDamProjectData = FillDamUiFromXmlInput.CreateDamProjectData(input);
+            CompareDamProjectData(actualDamProjectData, expectedDamProjectData);
+        }
     }
 }
 
Index: DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/DamEngineIo/FillXmlInputFromDamUi.cs
===================================================================
diff -u -r2578 -r2612
--- DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/DamEngineIo/FillXmlInputFromDamUi.cs	(.../FillXmlInputFromDamUi.cs)	(revision 2578)
+++ DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/DamEngineIo/FillXmlInputFromDamUi.cs	(.../FillXmlInputFromDamUi.cs)	(revision 2612)
@@ -403,6 +403,11 @@
             {
                 throw new NullReferenceException("No locations defined in this project");
             }
+            if (damProjectData.DamProjectCalculationSpecification.CurrentSpecification == null)
+            {
+                // This situation should never occur in the UI. Tested because of the check on RiverLevelLow in the code below
+                throw new NullReferenceException("No calculation type specified");
+            }
             foreach (Location location in dike.Locations)
             {
                 if (location.Scenarios == null)
@@ -418,6 +423,16 @@
                             throw new NullReferenceException(string.Format("Location '{0}', scenario '{1}' has no river level", 
                                 location.Name, scenario.LocationScenarioID));
                         }
+                        // In code above is tested that CurrentSpecification exists
+                        if (damProjectData.DamProjectCalculationSpecification.CurrentSpecification.FailureMechanismSystemType ==
+                                FailureMechanismSystemType.StabilityOutside)
+                        {
+                            if (scenario.RiverLevelLow == null)
+                            {
+                                throw new NullReferenceException(string.Format("Location '{0}', scenario '{1}' has no river level low",
+                                    location.Name, scenario.LocationScenarioID));
+                            }
+                        }
                     }
                 }
             }