Index: Ringtoets/Integration/src/Ringtoets.Integration.Plugin/AssessmentSectionMerger.cs
===================================================================
diff -u -r31fe9de8d235e39e7cfd722a89bc39af495f99a7 -r36fb70b04307e0805488e2862cd94b1820f6bb1e
--- Ringtoets/Integration/src/Ringtoets.Integration.Plugin/AssessmentSectionMerger.cs	(.../AssessmentSectionMerger.cs)	(revision 31fe9de8d235e39e7cfd722a89bc39af495f99a7)
+++ Ringtoets/Integration/src/Ringtoets.Integration.Plugin/AssessmentSectionMerger.cs	(.../AssessmentSectionMerger.cs)	(revision 36fb70b04307e0805488e2862cd94b1820f6bb1e)
@@ -131,6 +131,12 @@
                 LogCancelMessage();
                 return;
             }
+
+            if (mergeDataProvider.SelectedAssessmentSection == null || mergeDataProvider.SelectedFailureMechanisms == null)
+            {
+                LogError(Resources.AssessmentSectionMerger_No_AssessmentSection_selected);
+                return;
+            }
         }
 
         private string SelectProject()
Index: Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Properties/Resources.Designer.cs
===================================================================
diff -u -r03733ab29bedcd18c213b3d62b87080514a9a67b -r36fb70b04307e0805488e2862cd94b1820f6bb1e
--- Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 03733ab29bedcd18c213b3d62b87080514a9a67b)
+++ Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 36fb70b04307e0805488e2862cd94b1820f6bb1e)
@@ -142,6 +142,15 @@
         }
         
         /// <summary>
+        ///   Looks up a localized string similar to Er is geen traject geselecteerd..
+        /// </summary>
+        public static string AssessmentSectionMerger_No_AssessmentSection_selected {
+            get {
+                return ResourceManager.GetString("AssessmentSectionMerger_No_AssessmentSection_selected", resourceCulture);
+            }
+        }
+        
+        /// <summary>
         ///   Looks up a localized string similar to Er zijn geen trajecten gevonden die samengevoegd kunnen worden..
         /// </summary>
         public static string AssessmentSectionMerger_No_matching_AssessmentSections {
Index: Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Properties/Resources.resx
===================================================================
diff -u -r03733ab29bedcd18c213b3d62b87080514a9a67b -r36fb70b04307e0805488e2862cd94b1820f6bb1e
--- Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Properties/Resources.resx	(.../Resources.resx)	(revision 03733ab29bedcd18c213b3d62b87080514a9a67b)
+++ Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Properties/Resources.resx	(.../Resources.resx)	(revision 36fb70b04307e0805488e2862cd94b1820f6bb1e)
@@ -188,4 +188,7 @@
   <data name="AssessmentSectionMerger_No_matching_AssessmentSections" xml:space="preserve">
     <value>Er zijn geen trajecten gevonden die samengevoegd kunnen worden.</value>
   </data>
+  <data name="AssessmentSectionMerger_No_AssessmentSection_selected" xml:space="preserve">
+    <value>Er is geen traject geselecteerd.</value>
+  </data>
 </root>
\ No newline at end of file
Index: Ringtoets/Integration/test/Ringtoets.Integration.Plugin.Test/AssessmentSectionMergerTest.cs
===================================================================
diff -u -r31fe9de8d235e39e7cfd722a89bc39af495f99a7 -r36fb70b04307e0805488e2862cd94b1820f6bb1e
--- Ringtoets/Integration/test/Ringtoets.Integration.Plugin.Test/AssessmentSectionMergerTest.cs	(.../AssessmentSectionMergerTest.cs)	(revision 31fe9de8d235e39e7cfd722a89bc39af495f99a7)
+++ Ringtoets/Integration/test/Ringtoets.Integration.Plugin.Test/AssessmentSectionMergerTest.cs	(.../AssessmentSectionMergerTest.cs)	(revision 36fb70b04307e0805488e2862cd94b1820f6bb1e)
@@ -258,5 +258,70 @@
             TestHelper.AssertLogMessageWithLevelIsGenerated(call, new Tuple<string, LogLevelConstant>("Importeren van gegevens is geannuleerd.", LogLevelConstant.Info), 1);
             mocks.VerifyAll();
         }
+
+        [Test]
+        public void GivenMatchedAssessmentSection_WhenMergeDataProviderReturnTrueButSelectedAssessmentSectionNull_ThenLogErrorMessageAndAbort()
+        {
+            // Given
+            var mocks = new MockRepository();
+            var inquiryHelper = mocks.StrictMock<IInquiryHelper>();
+            inquiryHelper.Expect(helper => helper.GetSourceFileLocation(null)).IgnoreArguments().Return(string.Empty);
+            var comparer = mocks.StrictMock<IAssessmentSectionMergeComparer>();
+            comparer.Expect(c => c.Compare(null, null)).IgnoreArguments().Return(true);
+            var mergeDataProvider = mocks.StrictMock<IMergeDataProvider>();
+            mergeDataProvider.Expect(mdp => mdp.SelectData(null)).IgnoreArguments().Return(true);
+            mergeDataProvider.Expect(mdp => mdp.SelectedAssessmentSection).Return(null);
+            mocks.ReplayAll();
+
+            Action<string, AssessmentSectionsOwner> getAssessmentSectionsAction = (path, owner) =>
+            {
+                owner.AssessmentSections = new []
+                {
+                    new AssessmentSection(AssessmentSectionComposition.Dike)
+                };
+            };
+
+            var merger = new AssessmentSectionMerger(inquiryHelper, getAssessmentSectionsAction, comparer, mergeDataProvider);
+
+            // When
+            Action call = () => merger.StartMerge(new AssessmentSection(AssessmentSectionComposition.Dike));
+
+            // Then
+            TestHelper.AssertLogMessageWithLevelIsGenerated(call, new Tuple<string, LogLevelConstant>("Er is geen traject geselecteerd.", LogLevelConstant.Error), 1);
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void GivenMatchedAssessmentSection_WhenMergeDataProviderReturnTrueButSelectedFailureMechanismsnNull_ThenLogErrorMessageAndAbort()
+        {
+            // Given
+            var mocks = new MockRepository();
+            var inquiryHelper = mocks.StrictMock<IInquiryHelper>();
+            inquiryHelper.Expect(helper => helper.GetSourceFileLocation(null)).IgnoreArguments().Return(string.Empty);
+            var comparer = mocks.StrictMock<IAssessmentSectionMergeComparer>();
+            comparer.Expect(c => c.Compare(null, null)).IgnoreArguments().Return(true);
+            var mergeDataProvider = mocks.StrictMock<IMergeDataProvider>();
+            mergeDataProvider.Expect(mdp => mdp.SelectData(null)).IgnoreArguments().Return(true);
+            mergeDataProvider.Expect(mdp => mdp.SelectedAssessmentSection).Return(new AssessmentSection(AssessmentSectionComposition.Dike));
+            mergeDataProvider.Expect(mdp => mdp.SelectedFailureMechanisms).Return(null);
+            mocks.ReplayAll();
+
+            Action<string, AssessmentSectionsOwner> getAssessmentSectionsAction = (path, owner) =>
+            {
+                owner.AssessmentSections = new []
+                {
+                    new AssessmentSection(AssessmentSectionComposition.Dike)
+                };
+            };
+
+            var merger = new AssessmentSectionMerger(inquiryHelper, getAssessmentSectionsAction, comparer, mergeDataProvider);
+
+            // When
+            Action call = () => merger.StartMerge(new AssessmentSection(AssessmentSectionComposition.Dike));
+
+            // Then
+            TestHelper.AssertLogMessageWithLevelIsGenerated(call, new Tuple<string, LogLevelConstant>("Er is geen traject geselecteerd.", LogLevelConstant.Error), 1);
+            mocks.VerifyAll();
+        }
     }
 }
\ No newline at end of file