Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/DikesDesign/DesignCalculator.cs
===================================================================
diff -u -r1376 -r1394
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/DikesDesign/DesignCalculator.cs	(.../DesignCalculator.cs)	(revision 1376)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/DikesDesign/DesignCalculator.cs	(.../DesignCalculator.cs)	(revision 1394)
@@ -43,10 +43,18 @@
         /// </summary>
         /// <param name="damProjectData">The dam project data.</param>
         /// <returns></returns>
-        public List<LogMessage> Execute(DamProjectData damProjectData)
+        public void Execute(DamProjectData damProjectData)
         {
             damProjectData.DesignCalculations = new List<DesignResult>();
-            var calculationMessages = new List<LogMessage>();
+            if (damProjectData.CalculationMessages == null)
+            {
+                damProjectData.CalculationMessages = new List<LogMessage>();
+            }
+            else
+            {
+                damProjectData.CalculationMessages.Clear();
+            }
+            
             for (int locationIndex = 0; locationIndex < damProjectData.Dike.Locations.Count; locationIndex++)
             {
                 var location = damProjectData.Dike.Locations[locationIndex];
@@ -92,13 +100,13 @@
                                     case AnalysisType.AdaptGeometry:
                                         PerformDesignCalculation(
                                             kernelWrapper, kernelDataInput, kernelDataOutput,
-                                            damKernelInput, designScenario, calculationMessages,
+                                            damKernelInput, designScenario, damProjectData.CalculationMessages,
                                             damProjectData.DesignCalculations);
                                         break;
                                     case AnalysisType.NoAdaption:
                                         DesignCalculatorSingle.PerformSingleCalculation(
                                             kernelWrapper, kernelDataInput, kernelDataOutput,
-                                            damKernelInput, designScenario, calculationMessages,
+                                            damKernelInput, designScenario, damProjectData.CalculationMessages,
                                             damProjectData.DesignCalculations);
                                         break;
 
@@ -112,28 +120,26 @@
                                 }
                                 if (prepareResult == PrepareResult.Failed)
                                 {
-                                    calculationMessages.Add(new LogMessage(LogMessageType.Error, null,
+                                    damProjectData.CalculationMessages.Add(new LogMessage(LogMessageType.Error, null,
                                         string.Format(Resources.DesignCalculatorPrepareError,
                                         location.Name,
-                                        soiProfileProbability.ToString(),
+                                        soiProfileProbability,
                                         designScenario.LocationScenarioID)));
                                 }
                             }
                         }
                         catch (Exception e)
                         {
-                            calculationMessages.Add(new LogMessage(LogMessageType.Error, null,
+                            damProjectData.CalculationMessages.Add(new LogMessage(LogMessageType.Error, null,
                                 string.Format(Resources.DesignCalculatorGeneralException,
                                 location.Name,
-                                soiProfileProbability.ToString(),
+                                soiProfileProbability,
                                 designScenario.LocationScenarioID,
                                 e.Message)));
                         }
-
                     }
                 }
             }
-            return calculationMessages;
         }
 
         /// <summary>
Index: DamEngine/trunk/src/Deltares.DamEngine.Interface/EngineInterface.cs
===================================================================
diff -u -r1192 -r1394
--- DamEngine/trunk/src/Deltares.DamEngine.Interface/EngineInterface.cs	(.../EngineInterface.cs)	(revision 1192)
+++ DamEngine/trunk/src/Deltares.DamEngine.Interface/EngineInterface.cs	(.../EngineInterface.cs)	(revision 1394)
@@ -167,18 +167,17 @@
             {
                 case DamProjectType.AssessmentRegional:
                     var regionalScenariosCalculator = new RegionalScenariosCalculation();
-                    calculationMessages = regionalScenariosCalculator.Execute(DamProjectData);
+                    regionalScenariosCalculator.Execute(DamProjectData);
                     regionalScenariosCalculator.GetResults();
                     break;
                 case DamProjectType.Operational:
                     throw new NotImplementedException();
                 case DamProjectType.Design:
                     DesignCalculator designCalculator = new DesignCalculator();
 
-                    calculationMessages = designCalculator.Execute(DamProjectData);
+                    designCalculator.Execute(DamProjectData);
                     break;
             }
-            DamProjectData.CalculationMessages = calculationMessages;
             Output output = FillXmlOutputFromDam.CreateOutput(DamProjectData);
             outputXml = DamXmlSerialization.SaveOutputAsXmlString(output);
             SendMessage(new LogMessage() { MessageType = LogMessageType.Info, Message = Resources.EndCalculation });
Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/DikesAssessmentRegional/RegionalScenariosCalculation.cs
===================================================================
diff -u -r1388 -r1394
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/DikesAssessmentRegional/RegionalScenariosCalculation.cs	(.../RegionalScenariosCalculation.cs)	(revision 1388)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/DikesAssessmentRegional/RegionalScenariosCalculation.cs	(.../RegionalScenariosCalculation.cs)	(revision 1394)
@@ -70,7 +70,7 @@
         /// </summary>
         /// <param name="aDamProjectData">a dam project data.</param>
         /// <returns></returns>
-        public List<LogMessage> Execute(DamProjectData aDamProjectData)
+        public void Execute(DamProjectData aDamProjectData)
         {
             damProjectData = aDamProjectData;
             if (damProjectData.CalculationMessages == null)
@@ -92,7 +92,6 @@
             evaluationJob = damProjectData.GetEvaluationJob();
             Run();
             evaluationJob.AttachResults(aDamProjectData.LocationJobs);
-            return damProjectData.CalculationMessages;
         }
 
         #region ICalculation Members