Index: dam engine/trunk/src/Deltares.DamEngine.Io/DamOutput.cs
===================================================================
diff -u -r416 -r418
--- dam engine/trunk/src/Deltares.DamEngine.Io/DamOutput.cs	(.../DamOutput.cs)	(revision 416)
+++ dam engine/trunk/src/Deltares.DamEngine.Io/DamOutput.cs	(.../DamOutput.cs)	(revision 418)
@@ -3017,8 +3017,6 @@
         
         private MessageMessageType messageTypeField;
         
-        private bool messageTypeFieldSpecified;
-        
         private string message1Field;
         
         /// <remarks/>
@@ -3033,17 +3031,6 @@
         }
         
         /// <remarks/>
-        [System.Xml.Serialization.XmlIgnoreAttribute()]
-        public bool MessageTypeSpecified {
-            get {
-                return this.messageTypeFieldSpecified;
-            }
-            set {
-                this.messageTypeFieldSpecified = value;
-            }
-        }
-        
-        /// <remarks/>
         [System.Xml.Serialization.XmlAttributeAttribute("Message")]
         public string Message1 {
             get {
Index: dam engine/trunk/Xsds Liquid/Message.xsd
===================================================================
diff -u -r355 -r418
--- dam engine/trunk/Xsds Liquid/Message.xsd	(.../Message.xsd)	(revision 355)
+++ dam engine/trunk/Xsds Liquid/Message.xsd	(.../Message.xsd)	(revision 418)
@@ -2,7 +2,7 @@
 <!-- Created with Liquid XML Studio 1.0.8.0 (http://www.liquid-technologies.com) -->
 <xs:schema elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
   <xs:complexType name="Message">
-    <xs:attribute name="MessageType">
+    <xs:attribute name="MessageType" use="required">
       <xs:simpleType>
         <xs:restriction base="xs:string">
           <xs:enumeration value="Error" />
@@ -11,6 +11,6 @@
         </xs:restriction>
       </xs:simpleType>
     </xs:attribute>
-    <xs:attribute name="Message" type="xs:string" />
+    <xs:attribute name="Message" type="xs:string" use="required" />
   </xs:complexType>
 </xs:schema>
\ No newline at end of file
Index: dam engine/trunk/src/Deltares.DamEngine.Io.Tests/DamXmlSerializationTests.cs
===================================================================
diff -u -r415 -r418
--- dam engine/trunk/src/Deltares.DamEngine.Io.Tests/DamXmlSerializationTests.cs	(.../DamXmlSerializationTests.cs)	(revision 415)
+++ dam engine/trunk/src/Deltares.DamEngine.Io.Tests/DamXmlSerializationTests.cs	(.../DamXmlSerializationTests.cs)	(revision 418)
@@ -73,6 +73,10 @@
         private void CompareOutput(Output expected, Output actual)
         {
             Assert.AreEqual(expected.Results.CalculationMessages.Length, actual.Results.CalculationMessages.Length);
+            Assert.AreEqual(expected.Results.CalculationMessages[0].Message1, actual.Results.CalculationMessages[0].Message1);
+            Assert.AreEqual(expected.Results.CalculationMessages[0].MessageType, actual.Results.CalculationMessages[0].MessageType);
+            Assert.AreEqual(expected.Results.CalculationMessages[1].Message1, actual.Results.CalculationMessages[1].Message1);
+            Assert.AreEqual(expected.Results.CalculationMessages[1].MessageType, actual.Results.CalculationMessages[1].MessageType);
         }
     }