Index: DamEngine/trunk/src/Deltares.DamEngine.Interface/EngineInterface.cs
===================================================================
diff -u -r1432 -r1553
--- DamEngine/trunk/src/Deltares.DamEngine.Interface/EngineInterface.cs	(.../EngineInterface.cs)	(revision 1432)
+++ DamEngine/trunk/src/Deltares.DamEngine.Interface/EngineInterface.cs	(.../EngineInterface.cs)	(revision 1553)
@@ -150,6 +150,22 @@
         public string Validate()
         {
             SendMessage(new LogMessage() { MessageType = LogMessageType.Info, Message = Resources.StartValidation });
+            List<LogMessage> validationMessages = null;
+            //validationMessages = DamProjectData.Validate(); or something like this....
+            // Local validation can give messages and these have to be added to the results but note that there
+            // already can be messages added by instantiation of the interface too. So add the local to the global
+            if (validationMessages != null && validationMessages.Count > 0)
+            {
+                DamProjectData.CalculationMessages.AddRange(validationMessages);
+            }
+            // Now check if there are any messages at all, if so return them.
+            if (DamProjectData.CalculationMessages.Count > 0)
+            {
+                Output output = FillXmlOutputFromDam.CreateOutput(DamProjectData);
+                string outputXml = DamXmlSerialization.SaveOutputAsXmlString(output);
+                SendMessage(new LogMessage() { MessageType = LogMessageType.Info, Message = Resources.EndValidation });
+                return outputXml;
+            }
             SendMessage(new LogMessage() { MessageType = LogMessageType.Info, Message = Resources.EndValidation });
             return null;
         }
@@ -163,7 +179,6 @@
             string outputXml;
             SendMessage(new LogMessage() { MessageType = LogMessageType.Info, Message = Resources.StartCalculation });
 
-            List<LogMessage> calculationMessages = null;
             switch (DamProjectData.DamProjectType)
             {
                 case DamProjectType.AssessmentRegional: