Index: Ringtoets/GrassCoverErosionOutwards/test/Ringtoets.GrassCoverErosionOutwards.Forms.Test/Views/GrassCoverErosionOutwardsFailureMechanismSectionResultRowTest.cs
===================================================================
diff -u -ra6ebd668680c82a4b7822d979c7be3c3ad11ff7b -re1f407b3d93adfa477726ede6ba785c3a7eac991
--- Ringtoets/GrassCoverErosionOutwards/test/Ringtoets.GrassCoverErosionOutwards.Forms.Test/Views/GrassCoverErosionOutwardsFailureMechanismSectionResultRowTest.cs	(.../GrassCoverErosionOutwardsFailureMechanismSectionResultRowTest.cs)	(revision a6ebd668680c82a4b7822d979c7be3c3ad11ff7b)
+++ Ringtoets/GrassCoverErosionOutwards/test/Ringtoets.GrassCoverErosionOutwards.Forms.Test/Views/GrassCoverErosionOutwardsFailureMechanismSectionResultRowTest.cs	(.../GrassCoverErosionOutwardsFailureMechanismSectionResultRowTest.cs)	(revision e1f407b3d93adfa477726ede6ba785c3a7eac991)
@@ -146,6 +146,33 @@
         }
 
         [Test]
+        public void Constructor_AssemblyThrowsException_ExpectedColumnStates()
+        {
+            // Setup
+            FailureMechanismSection section = FailureMechanismSectionTestFactory.CreateFailureMechanismSection();
+            var result = new GrassCoverErosionOutwardsFailureMechanismSectionResult(section);
+
+            using (new AssemblyToolCalculatorFactoryConfig())
+            {
+                var calculatorfactory = (TestAssemblyToolCalculatorFactory)AssemblyToolCalculatorFactory.Instance;
+                FailureMechanismSectionAssemblyCalculatorStub calculator = calculatorfactory.LastCreatedFailureMechanismSectionAssemblyCalculator;
+                calculator.ThrowExceptionOnCalculate = true;
+
+                // Call
+                var row = new GrassCoverErosionOutwardsFailureMechanismSectionResultRow(result, ConstructionProperties);
+
+                // Assert
+                IDictionary<int, DataGridViewColumnStateDefinition> columnStateDefinitions = row.ColumnStateDefinitions;
+                const string expectedErrorText = "Message";
+
+                Assert.AreEqual(expectedErrorText, columnStateDefinitions[ConstructionProperties.SimpleAssemblyCategoryGroupIndex].ErrorText);
+                Assert.AreEqual(expectedErrorText, columnStateDefinitions[ConstructionProperties.DetailedAssemblyCategoryGroupIndex].ErrorText);
+                Assert.AreEqual(expectedErrorText, columnStateDefinitions[ConstructionProperties.TailorMadeAssemblyCategoryGroupIndex].ErrorText);
+                Assert.AreEqual(expectedErrorText, columnStateDefinitions[ConstructionProperties.CombinedAssemblyCategoryGroupIndex].ErrorText);
+            }
+        }
+
+        [Test]
         public void UseManualAssemblyCategoryGroup_SetNewValue_NotifyObserversAndPropertyChanged()
         {
             // Setup
@@ -206,6 +233,86 @@
             }
         }
 
+        [Test]
+        public void GivenRowWithoutAssemblyErrors_WhenUpdatingAndAssemblyThrowsException_ThenAssemblyGroupSetToNone()
+        {
+            // Given
+            var random = new Random(39);
+            FailureMechanismSection section = FailureMechanismSectionTestFactory.CreateFailureMechanismSection();
+            var result = new GrassCoverErosionOutwardsFailureMechanismSectionResult(section);
+
+            using (new AssemblyToolCalculatorFactoryConfig())
+            {
+                var calculatorfactory = (TestAssemblyToolCalculatorFactory)AssemblyToolCalculatorFactory.Instance;
+                FailureMechanismSectionAssemblyCalculatorStub calculator = calculatorfactory.LastCreatedFailureMechanismSectionAssemblyCalculator;
+                calculator.SimpleAssessmentAssemblyOutput = new FailureMechanismSectionAssembly(
+                    random.NextDouble(),
+                    random.NextEnumValue<FailureMechanismSectionAssemblyCategoryGroup>());
+                calculator.DetailedAssessmentAssemblyGroupOutput = random.NextEnumValue<FailureMechanismSectionAssemblyCategoryGroup>();
+                calculator.TailorMadeAssemblyCategoryOutput = random.NextEnumValue<FailureMechanismSectionAssemblyCategoryGroup>();
+                calculator.CombinedAssemblyCategoryOutput = random.NextEnumValue<FailureMechanismSectionAssemblyCategoryGroup>();
+
+                var row = new GrassCoverErosionOutwardsFailureMechanismSectionResultRow(result, ConstructionProperties);
+
+                // Precondition
+                Assert.AreEqual(FailureMechanismSectionResultRowHelper.GetCategoryGroupDisplayname(calculator.SimpleAssessmentAssemblyOutput.Group),
+                                row.SimpleAssemblyCategoryGroup);
+                Assert.AreEqual(FailureMechanismSectionResultRowHelper.GetCategoryGroupDisplayname(calculator.DetailedAssessmentAssemblyGroupOutput.Value),
+                                row.DetailedAssemblyCategoryGroup);
+                Assert.AreEqual(FailureMechanismSectionResultRowHelper.GetCategoryGroupDisplayname(calculator.TailorMadeAssemblyCategoryOutput.Value),
+                                row.TailorMadeAssemblyCategoryGroup);
+                Assert.AreEqual(FailureMechanismSectionResultRowHelper.GetCategoryGroupDisplayname(calculator.CombinedAssemblyCategoryOutput.Value),
+                                row.CombinedAssemblyCategoryGroup);
+
+                // When
+                calculator.ThrowExceptionOnCalculate = true;
+                row.SimpleAssessmentResult = SimpleAssessmentResultType.AssessFurther;
+
+                // Then
+                string expectedAssemblyDisplayName = FailureMechanismSectionResultRowHelper.GetCategoryGroupDisplayname(FailureMechanismSectionAssemblyCategoryGroup.None);
+                Assert.AreEqual(expectedAssemblyDisplayName, row.SimpleAssemblyCategoryGroup);
+                Assert.AreEqual(expectedAssemblyDisplayName, row.DetailedAssemblyCategoryGroup);
+                Assert.AreEqual(expectedAssemblyDisplayName, row.TailorMadeAssemblyCategoryGroup);
+                Assert.AreEqual(expectedAssemblyDisplayName, row.CombinedAssemblyCategoryGroup);
+            }
+        }
+
+        [Test]
+        public void GivenRowWithAssemblyErrors_WhenUpdatingAndAssemblyDoesNotThrowException_ThenExpectedColumnStates()
+        {
+            // Given
+            FailureMechanismSection section = FailureMechanismSectionTestFactory.CreateFailureMechanismSection();
+            var result = new GrassCoverErosionOutwardsFailureMechanismSectionResult(section);
+
+            using (new AssemblyToolCalculatorFactoryConfig())
+            {
+                var calculatorfactory = (TestAssemblyToolCalculatorFactory)AssemblyToolCalculatorFactory.Instance;
+                FailureMechanismSectionAssemblyCalculatorStub calculator = calculatorfactory.LastCreatedFailureMechanismSectionAssemblyCalculator;
+                calculator.ThrowExceptionOnCalculate = true;
+
+                var row = new GrassCoverErosionOutwardsFailureMechanismSectionResultRow(result, ConstructionProperties);
+
+                // Precondition
+                IDictionary<int, DataGridViewColumnStateDefinition> columnStateDefinitions = row.ColumnStateDefinitions;
+                const string expectedErrorText = "Message";
+
+                Assert.AreEqual(expectedErrorText, columnStateDefinitions[ConstructionProperties.SimpleAssemblyCategoryGroupIndex].ErrorText);
+                Assert.AreEqual(expectedErrorText, columnStateDefinitions[ConstructionProperties.DetailedAssemblyCategoryGroupIndex].ErrorText);
+                Assert.AreEqual(expectedErrorText, columnStateDefinitions[ConstructionProperties.TailorMadeAssemblyCategoryGroupIndex].ErrorText);
+                Assert.AreEqual(expectedErrorText, columnStateDefinitions[ConstructionProperties.CombinedAssemblyCategoryGroupIndex].ErrorText);
+
+                // When
+                calculator.ThrowExceptionOnCalculate = false;
+                row.SimpleAssessmentResult = SimpleAssessmentResultType.AssessFurther;
+
+                // Then
+                Assert.AreEqual(string.Empty, columnStateDefinitions[ConstructionProperties.SimpleAssemblyCategoryGroupIndex].ErrorText);
+                Assert.AreEqual(string.Empty, columnStateDefinitions[ConstructionProperties.DetailedAssemblyCategoryGroupIndex].ErrorText);
+                Assert.AreEqual(string.Empty, columnStateDefinitions[ConstructionProperties.TailorMadeAssemblyCategoryGroupIndex].ErrorText);
+                Assert.AreEqual(string.Empty, columnStateDefinitions[ConstructionProperties.CombinedAssemblyCategoryGroupIndex].ErrorText);
+            }
+        }
+
         #region Registration
 
         [Test]