Index: Ringtoets/Integration/src/Ringtoets.Integration.Forms/Views/SectionResultRows/GrassCoverSlipOffOutwardsSectionResultRow.cs
===================================================================
diff -u -rf2cb20c760b6830245f781b0527fff6f6a6e8795 -r4dbb8c9e658bb02d5f1ff5aaf5dc3b45fc1c47ac
--- Ringtoets/Integration/src/Ringtoets.Integration.Forms/Views/SectionResultRows/GrassCoverSlipOffOutwardsSectionResultRow.cs	(.../GrassCoverSlipOffOutwardsSectionResultRow.cs)	(revision f2cb20c760b6830245f781b0527fff6f6a6e8795)
+++ Ringtoets/Integration/src/Ringtoets.Integration.Forms/Views/SectionResultRows/GrassCoverSlipOffOutwardsSectionResultRow.cs	(.../GrassCoverSlipOffOutwardsSectionResultRow.cs)	(revision 4dbb8c9e658bb02d5f1ff5aaf5dc3b45fc1c47ac)
@@ -252,12 +252,21 @@
 
         private void UpdateDerivedData()
         {
+            ResetErrorTexts();
             TryGetSimpleAssemblyCategoryGroup();
             TryGetDetailedAssemblyCategoryGroup();
             TryGetTailorMadeAssemblyCategoryGroup();
             TryGetCombinedAssemblyCategoryGroup();
         }
 
+        private void ResetErrorTexts()
+        {
+            ColumnStateDefinitions[simpleAssemblyCategoryGroupIndex].ErrorText = string.Empty;
+            ColumnStateDefinitions[detailedAssemblyCategoryGroupIndex].ErrorText = string.Empty;
+            ColumnStateDefinitions[tailorMadeAssemblyCategoryGroupIndex].ErrorText = string.Empty;
+            ColumnStateDefinitions[combinedAssemblyCategoryGroupIndex].ErrorText = string.Empty;
+        }
+
         private void TryGetSimpleAssemblyCategoryGroup()
         {
             try
@@ -267,6 +276,7 @@
             catch (AssemblyException e)
             {
                 simpleAssemblyCategoryGroup = FailureMechanismSectionAssemblyCategoryGroup.None;
+                ColumnStateDefinitions[simpleAssemblyCategoryGroupIndex].ErrorText = e.Message;
             }
         }
 
@@ -279,6 +289,7 @@
             catch (AssemblyException e)
             {
                 detailedAssemblyCategoryGroup = FailureMechanismSectionAssemblyCategoryGroup.None;
+                ColumnStateDefinitions[detailedAssemblyCategoryGroupIndex].ErrorText = e.Message;
             }
         }
 
@@ -291,6 +302,7 @@
             catch (AssemblyException e)
             {
                 tailorMadeAssemblyCategoryGroup = FailureMechanismSectionAssemblyCategoryGroup.None;
+                ColumnStateDefinitions[tailorMadeAssemblyCategoryGroupIndex].ErrorText = e.Message;
             }
         }
 
@@ -303,6 +315,7 @@
             catch (AssemblyException e)
             {
                 combinedAssemblyCategoryGroup = FailureMechanismSectionAssemblyCategoryGroup.None;
+                ColumnStateDefinitions[combinedAssemblyCategoryGroupIndex].ErrorText = e.Message;
             }
         }