Index: Riskeer/GrassCoverErosionOutwards/src/Riskeer.GrassCoverErosionOutwards.Service/GrassCoverErosionOutwardsWaveConditionsCalculationService.cs
===================================================================
diff -u -r3d2eadd118350d7ab9bbcac167c48d3395654cfd -rc5fc4d9cca413fddc9a430ddca1fe0a0e40b0fcc
--- Riskeer/GrassCoverErosionOutwards/src/Riskeer.GrassCoverErosionOutwards.Service/GrassCoverErosionOutwardsWaveConditionsCalculationService.cs	(.../GrassCoverErosionOutwardsWaveConditionsCalculationService.cs)	(revision 3d2eadd118350d7ab9bbcac167c48d3395654cfd)
+++ Riskeer/GrassCoverErosionOutwards/src/Riskeer.GrassCoverErosionOutwards.Service/GrassCoverErosionOutwardsWaveConditionsCalculationService.cs	(.../GrassCoverErosionOutwardsWaveConditionsCalculationService.cs)	(revision c5fc4d9cca413fddc9a430ddca1fe0a0e40b0fcc)
@@ -1,4 +1,4 @@
-// Copyright (C) Stichting Deltares 2019. All rights reserved.
+// Copyright (C) Stichting Deltares 2019. All rights reserved.
 //
 // This file is part of Riskeer.
 //
@@ -111,6 +111,11 @@
                     waveRunUpOutput = CalculateWaveRunUp(calculation, failureMechanism, assessmentSection, assessmentLevel);
                 }
 
+                if (Canceled)
+                {
+                    return;
+                }
+
                 IEnumerable<WaveConditionsOutput> waveImpactOutput = null;
                 if (calculationType == GrassCoverErosionOutwardsWaveConditionsCalculationType.Both
                     || calculationType == GrassCoverErosionOutwardsWaveConditionsCalculationType.WaveImpact)
Index: Riskeer/GrassCoverErosionOutwards/test/Riskeer.GrassCoverErosionOutwards.Integration.Test/GrassCoverErosionOutwardsWaveConditionsCalculationActivityIntegrationTest.cs
===================================================================
diff -u -r5bc15e683e6b36838c0fb3f46929abf002e70105 -rc5fc4d9cca413fddc9a430ddca1fe0a0e40b0fcc
--- Riskeer/GrassCoverErosionOutwards/test/Riskeer.GrassCoverErosionOutwards.Integration.Test/GrassCoverErosionOutwardsWaveConditionsCalculationActivityIntegrationTest.cs	(.../GrassCoverErosionOutwardsWaveConditionsCalculationActivityIntegrationTest.cs)	(revision 5bc15e683e6b36838c0fb3f46929abf002e70105)
+++ Riskeer/GrassCoverErosionOutwards/test/Riskeer.GrassCoverErosionOutwards.Integration.Test/GrassCoverErosionOutwardsWaveConditionsCalculationActivityIntegrationTest.cs	(.../GrassCoverErosionOutwardsWaveConditionsCalculationActivityIntegrationTest.cs)	(revision c5fc4d9cca413fddc9a430ddca1fe0a0e40b0fcc)
@@ -389,7 +389,7 @@
                     string[] msgs = messages.ToArray();
                     RoundedDouble firstWaterLevel = GetWaterLevels(calculation, failureMechanism, assessmentSection).First();
 
-                    Assert.AreEqual(12, msgs.Length);
+                    Assert.AreEqual(10, msgs.Length);
                     Assert.AreEqual($"Golfcondities berekenen voor '{calculation.Name}' is gestart.", msgs[0]);
                     CalculationServiceTestHelper.AssertValidationStartMessage(msgs[1]);
                     CalculationServiceTestHelper.AssertValidationEndMessage(msgs[2]);
@@ -401,10 +401,7 @@
                     Assert.AreEqual($"Berekening voor waterstand '{firstWaterLevel}' is beëindigd.", msgs[7]);
                     Assert.AreEqual("Berekening voor golfoploop is beëindigd.", msgs[8]);
 
-                    Assert.AreEqual("Berekening voor golfklap is gestart.", msgs[9]);
-                    Assert.AreEqual("Berekening voor golfklap is beëindigd.", msgs[10]);
-
-                    CalculationServiceTestHelper.AssertCalculationEndMessage(msgs[11]);
+                    CalculationServiceTestHelper.AssertCalculationEndMessage(msgs[9]);
                 });
 
                 Assert.AreEqual(ActivityState.Canceled, activity.State);