Index: Ringtoets/Common/src/Ringtoets.Common.IO/ReferenceLineMetaImporter.cs
===================================================================
diff -u -re3f0e0861e4d1f5faa32280e837777e8755b67d6 -r7d38bc43c1be859f9a410ed99c6dacb2a6f58126
--- Ringtoets/Common/src/Ringtoets.Common.IO/ReferenceLineMetaImporter.cs	(.../ReferenceLineMetaImporter.cs)	(revision e3f0e0861e4d1f5faa32280e837777e8755b67d6)
+++ Ringtoets/Common/src/Ringtoets.Common.IO/ReferenceLineMetaImporter.cs	(.../ReferenceLineMetaImporter.cs)	(revision 7d38bc43c1be859f9a410ed99c6dacb2a6f58126)
@@ -24,6 +24,7 @@
 using System.IO;
 using System.Linq;
 using System.Security;
+using System.Windows.Forms;
 using Core.Common.IO.Exceptions;
 using Core.Common.Utils.Builders;
 using Core.Common.Utils.Properties;
@@ -78,6 +79,8 @@
             targetItem.WrappedData.Id = assessmentSectionId;
             targetItem.WrappedData.ReferenceLine = selectedReferenceLineMeta;
 
+            targetItem.WrappedData.NotifyObservers();
+
             return true;
         }
 
@@ -163,6 +166,33 @@
                     }
                 } while (referenceLinesMeta != null);
             }
+
+            ValidateReferenceLineMetas();
         }
+
+        private void ValidateReferenceLineMetas()
+        {
+            var referenceLineMetasCount = referenceLineMetas.Select(rlm => rlm.AssessmentSectionId).Count();
+            var referenceLineMetasDistinctCount = referenceLineMetas.Select(rlm => rlm.AssessmentSectionId).Distinct().Count();
+
+            if (referenceLineMetasCount != referenceLineMetasDistinctCount)
+            {
+                var message = new FileReaderErrorMessageBuilder(shapeFilePath)
+                    .Build("De trajectid's niet uniek.");
+                log.Warn(message);
+
+                MessageBox.Show(message, "Fout", MessageBoxButtons.OK, MessageBoxIcon.Error);
+                return;
+            }
+
+            if (referenceLineMetas.Any(rlm => String.IsNullOrEmpty(rlm.AssessmentSectionId)))
+            {
+                var message = new FileReaderErrorMessageBuilder(shapeFilePath)
+                    .Build("De trajectid's zijn niet allemaal ingevuld.");
+                log.Warn(message);
+
+                MessageBox.Show(message, "Fout", MessageBoxButtons.OK, MessageBoxIcon.Error);
+            }
+        }
     }
 }
\ No newline at end of file