Index: Ringtoets/Common/src/Ringtoets.Common.Data/Exceptions/AssemblyCategoryConversionException.cs
===================================================================
diff -u
--- Ringtoets/Common/src/Ringtoets.Common.Data/Exceptions/AssemblyCategoryConversionException.cs	(revision 0)
+++ Ringtoets/Common/src/Ringtoets.Common.Data/Exceptions/AssemblyCategoryConversionException.cs	(revision c664a015d5ebcd9e4154f6a9bb48c8a09c2d0127)
@@ -0,0 +1,70 @@
+// Copyright (C) Stichting Deltares 2017. All rights reserved.
+//
+// This file is part of Ringtoets.
+//
+// Ringtoets is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+//
+// All names, logos, and references to "Deltares" are registered trademarks of
+// Stichting Deltares and remain full property of Stichting Deltares at all times.
+// All rights reserved.
+
+using System;
+using System.Runtime.Serialization;
+
+namespace Ringtoets.Common.Data.Exceptions
+{
+    /// <summary>
+    /// The exception that is thrown when converting assembly categories from the Assembly tool data was unsuccessful.
+    /// </summary>
+    [Serializable]
+    public class AssemblyCategoryConversionException : Exception
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AssemblyCategoryConversionException"/> class.
+        /// </summary>
+        public AssemblyCategoryConversionException() {}
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AssemblyCategoryConversionException"/> class
+        /// with a specified error message.
+        /// </summary>
+        /// <param name="message">The error message that explains the reason for the exception.</param>
+        public AssemblyCategoryConversionException(string message) : base(message) {}
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AssemblyCategoryConversionException"/> class
+        /// with a specified error message and a reference to the inner exception that is
+        /// the cause of this exception.
+        /// </summary>
+        /// <param name="message">The error message that explains the reason for the exception.</param>
+        /// <param name="inner">The exception that is the cause of the current exception, 
+        /// or a null reference if no inner exception is specified.</param>
+        public AssemblyCategoryConversionException(string message, Exception inner) : base(message, inner) {}
+
+        /// <summary>
+        /// Initializes a new instance of <see cref="AssemblyCategoryConversionException"/> with
+        /// serialized data.</summary>
+        /// <param name="info">The <see cref="SerializationInfo"/> that holds the serialized
+        /// object data about the exception being thrown.</param>
+        /// <param name="context">The <see cref="StreamingContext"/> that contains contextual
+        /// information about the source or destination.</param>
+        /// <exception cref="ArgumentNullException">The <paramref name="info"/> parameter is
+        /// <c>null</c>.</exception>
+        /// <exception cref="SerializationException">The class name is <c>null</c> or
+        /// <see cref="Exception.HResult" /> is zero (0).</exception>
+        protected AssemblyCategoryConversionException(SerializationInfo info, StreamingContext context) : base(info, context) {}
+
+        
+    }
+}
\ No newline at end of file
Index: Ringtoets/Common/src/Ringtoets.Common.Data/Ringtoets.Common.Data.csproj
===================================================================
diff -u -r4160a30705d657946461b76a5c443119cb78d437 -rc664a015d5ebcd9e4154f6a9bb48c8a09c2d0127
--- Ringtoets/Common/src/Ringtoets.Common.Data/Ringtoets.Common.Data.csproj	(.../Ringtoets.Common.Data.csproj)	(revision 4160a30705d657946461b76a5c443119cb78d437)
+++ Ringtoets/Common/src/Ringtoets.Common.Data/Ringtoets.Common.Data.csproj	(.../Ringtoets.Common.Data.csproj)	(revision c664a015d5ebcd9e4154f6a9bb48c8a09c2d0127)
@@ -42,6 +42,7 @@
     <Compile Include="DikeProfiles\IHasForeshoreProfile.cs" />
     <Compile Include="DikeProfiles\IUseBreakWater.cs" />
     <Compile Include="DikeProfiles\IUseForeshore.cs" />
+    <Compile Include="Exceptions\AssemblyCategoryConversionException.cs" />
     <Compile Include="Exceptions\IllustrationPointConversionException.cs" />
     <Compile Include="Exceptions\MechanismSurfaceLineException.cs" />
     <Compile Include="FailureMechanism\AssessmentLayerOneState.cs" />
Index: Ringtoets/Common/src/Ringtoets.Common.Service/AssemblyTool/AssemblyCategoryConverter.cs
===================================================================
diff -u -r8c111accea72ca8a9205a8615102e16168f62ce7 -rc664a015d5ebcd9e4154f6a9bb48c8a09c2d0127
--- Ringtoets/Common/src/Ringtoets.Common.Service/AssemblyTool/AssemblyCategoryConverter.cs	(.../AssemblyCategoryConverter.cs)	(revision 8c111accea72ca8a9205a8615102e16168f62ce7)
+++ Ringtoets/Common/src/Ringtoets.Common.Service/AssemblyTool/AssemblyCategoryConverter.cs	(.../AssemblyCategoryConverter.cs)	(revision c664a015d5ebcd9e4154f6a9bb48c8a09c2d0127)
@@ -25,6 +25,7 @@
 using System.Linq;
 using Ringtoets.AssemblyTool.Data.Output;
 using Ringtoets.Common.Data.AssemblyTool;
+using Ringtoets.Common.Data.Exceptions;
 
 namespace Ringtoets.Common.Service.AssemblyTool
 {
@@ -39,10 +40,9 @@
         /// <param name="result">The result to convert.</param>
         /// <returns>The converted categories.</returns>
         /// <exception cref="ArgumentNullException">Thrown when <paramref name="result"/> is <c>null</c>.</exception>
-        /// <exception cref="InvalidEnumArgumentException">Thrown when <see cref="AssessmentSectionAssemblyCategoryResultType"/>
-        /// is an invalid value.</exception>
-        /// <exception cref="NotSupportedException">Thrown when <see cref="AssessmentSectionAssemblyCategoryResultType"/>
-        /// is a valid value but unsupported.</exception>
+        /// <exception cref="AssemblyCategoryConversionException">Thrown when
+        /// <see cref="AssessmentSectionAssemblyCategoryResultType"/> is an invalid value 
+        /// or a valid value but unsupported.</exception>
         public static IEnumerable<AssessmentSectionAssemblyCategory> ConvertAssessmentSectionAssemblyCategories(
             IEnumerable<AssessmentSectionAssemblyCategoryResult> result)
         {
@@ -59,14 +59,20 @@
         /// </summary>
         /// <param name="result">The result to convert.</param>
         /// <returns>The converted category.</returns>
-        /// <exception cref="InvalidEnumArgumentException">Thrown when <see cref="AssessmentSectionAssemblyCategoryResultType"/>
-        /// is an invalid value.</exception>
-        /// <exception cref="NotSupportedException">Thrown when <see cref="AssessmentSectionAssemblyCategoryResultType"/>
-        /// is a valid value but unsupported.</exception>
+        /// <exception cref="AssemblyCategoryConversionException">Thrown when
+        /// <see cref="AssessmentSectionAssemblyCategoryResultType"/> is an invalid value 
+        /// or a valid value but unsupported.</exception>
         private static AssessmentSectionAssemblyCategory ConvertAssessmentSectionAssemblyCategory(AssessmentSectionAssemblyCategoryResult result)
         {
-            return new AssessmentSectionAssemblyCategory(result.LowerBoundary, result.UpperBoundary,
-                                                         ConvertAssessmentSectionAssemblyCategoryType(result.Category));
+            try
+            {
+                return new AssessmentSectionAssemblyCategory(result.LowerBoundary, result.UpperBoundary,
+                                                             ConvertAssessmentSectionAssemblyCategoryType(result.Category));
+            }
+            catch (Exception e) when (e is InvalidEnumArgumentException || e is NotSupportedException)
+            {
+                throw new AssemblyCategoryConversionException(e.Message, e);
+            }
         }
 
         /// <summary>
Index: Ringtoets/Common/test/Ringtoets.Common.Data.Test/Exceptions/AssemblyCategoryConversionExceptionTest.cs
===================================================================
diff -u
--- Ringtoets/Common/test/Ringtoets.Common.Data.Test/Exceptions/AssemblyCategoryConversionExceptionTest.cs	(revision 0)
+++ Ringtoets/Common/test/Ringtoets.Common.Data.Test/Exceptions/AssemblyCategoryConversionExceptionTest.cs	(revision c664a015d5ebcd9e4154f6a9bb48c8a09c2d0127)
@@ -0,0 +1,31 @@
+// Copyright (C) Stichting Deltares 2017. All rights reserved.
+//
+// This file is part of Ringtoets.
+//
+// Ringtoets is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+//
+// All names, logos, and references to "Deltares" are registered trademarks of
+// Stichting Deltares and remain full property of Stichting Deltares at all times.
+// All rights reserved.
+
+using System;
+using Core.Common.TestUtil;
+using NUnit.Framework;
+using Ringtoets.Common.Data.Exceptions;
+
+namespace Ringtoets.Common.Data.Test.Exceptions
+{
+    [TestFixture]
+    public class AssemblyCategoryConversionExceptionTest : CustomExceptionDesignGuidelinesTestFixture<AssemblyCategoryConversionException, Exception> {}
+}
\ No newline at end of file
Index: Ringtoets/Common/test/Ringtoets.Common.Data.Test/Ringtoets.Common.Data.Test.csproj
===================================================================
diff -u -r4160a30705d657946461b76a5c443119cb78d437 -rc664a015d5ebcd9e4154f6a9bb48c8a09c2d0127
--- Ringtoets/Common/test/Ringtoets.Common.Data.Test/Ringtoets.Common.Data.Test.csproj	(.../Ringtoets.Common.Data.Test.csproj)	(revision 4160a30705d657946461b76a5c443119cb78d437)
+++ Ringtoets/Common/test/Ringtoets.Common.Data.Test/Ringtoets.Common.Data.Test.csproj	(.../Ringtoets.Common.Data.Test.csproj)	(revision c664a015d5ebcd9e4154f6a9bb48c8a09c2d0127)
@@ -41,6 +41,7 @@
     <Compile Include="DikeProfiles\DikeProfileTest.cs" />
     <Compile Include="DikeProfiles\ForeshoreProfileCollectionTest.cs" />
     <Compile Include="DikeProfiles\ForeshoreProfileTest.cs" />
+    <Compile Include="Exceptions\AssemblyCategoryConversionExceptionTest.cs" />
     <Compile Include="Exceptions\IllustrationPointConversionExceptionTest.cs" />
     <Compile Include="Exceptions\MechanismSurfaceLineExceptionTest.cs" />
     <Compile Include="FailureMechanism\AssessmentLayerOneStateTest.cs" />
Index: Ringtoets/Common/test/Ringtoets.Common.Service.Test/AssemblyTool/AssemblyCategoryConverterTest.cs
===================================================================
diff -u -r8c111accea72ca8a9205a8615102e16168f62ce7 -rc664a015d5ebcd9e4154f6a9bb48c8a09c2d0127
--- Ringtoets/Common/test/Ringtoets.Common.Service.Test/AssemblyTool/AssemblyCategoryConverterTest.cs	(.../AssemblyCategoryConverterTest.cs)	(revision 8c111accea72ca8a9205a8615102e16168f62ce7)
+++ Ringtoets/Common/test/Ringtoets.Common.Service.Test/AssemblyTool/AssemblyCategoryConverterTest.cs	(.../AssemblyCategoryConverterTest.cs)	(revision c664a015d5ebcd9e4154f6a9bb48c8a09c2d0127)
@@ -27,6 +27,7 @@
 using NUnit.Framework;
 using Ringtoets.AssemblyTool.Data.Output;
 using Ringtoets.Common.Data.AssemblyTool;
+using Ringtoets.Common.Data.Exceptions;
 using Ringtoets.Common.Service.AssemblyTool;
 
 namespace Ringtoets.Common.Service.Test.AssemblyTool
@@ -79,8 +80,10 @@
             TestDelegate test = () => AssemblyCategoryConverter.ConvertAssessmentSectionAssemblyCategories(result);
 
             // Assert
-            const string expectedMessage = "The value of argument 'categoryType' (99) is invalid for Enum type 'AssessmentSectionAssemblyCategoryResultType'.";
-            TestHelper.AssertThrowsArgumentExceptionAndTestMessage<InvalidEnumArgumentException>(test, expectedMessage);
+            const string expectedMessage = "The value of argument 'categoryType' (99) is invalid for Enum type 'AssessmentSectionAssemblyCategoryResultType'.\r\nParameter name: categoryType";
+            var exception = Assert.Throws<AssemblyCategoryConversionException>(test);
+            Assert.AreEqual(expectedMessage, exception.Message);
+            Assert.IsInstanceOf<InvalidEnumArgumentException>(exception.InnerException);
         }
 
         [Test]