Index: Ringtoets/Common/src/Ringtoets.Common.IO/Readers/ConfigurationReader.cs
===================================================================
diff -u -re8d6d0512bc28b0af2bd1e8fae1f0bd9e976300c -r1d2bc8f06f058cf7bf75fffa684ceca7961ec1de
--- Ringtoets/Common/src/Ringtoets.Common.IO/Readers/ConfigurationReader.cs	(.../ConfigurationReader.cs)	(revision e8d6d0512bc28b0af2bd1e8fae1f0bd9e976300c)
+++ Ringtoets/Common/src/Ringtoets.Common.IO/Readers/ConfigurationReader.cs	(.../ConfigurationReader.cs)	(revision 1d2bc8f06f058cf7bf75fffa684ceca7961ec1de)
@@ -49,23 +49,32 @@
         /// Creates a new instance of <see cref="ConfigurationReader{TCalculationItem}"/>.
         /// </summary>
         /// <param name="xmlFilePath">The file path to the XML file.</param>
-        /// <param name="mainSchemaDefinition">A string representing the main schema definition.</param>
+        /// <param name="mainSchemaDefinition">A <c>string</c> representing the main schema definition.</param>
         /// <param name="nestedSchemaDefinitions">A <see cref="IDictionary{TKey,TValue}"/> containing
-        /// one or more nested schema definitions; the keys should represent unique file names by which
-        /// the schema definitions can be referenced from <paramref name="mainSchemaDefinition"/>, the
-        /// values should represent the corresponding schema definition strings.</param>
+        /// zero to more nested schema definitions. The keys should represent unique file names by which
+        /// the schema definitions can be referenced from <paramref name="mainSchemaDefinition"/>; the
+        /// values should represent their corresponding schema definition <c>string</c>.</param>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="nestedSchemaDefinitions"/>
+        /// is <c>null</c>.</exception>
         /// <exception cref="ArgumentException">Thrown when:
         /// <list type="bullet">
         /// <item><paramref name="xmlFilePath"/> is invalid.</item>
-        /// <item><paramref name="mainSchemaDefinition"/> is <c>null</c> or empty.</item>
-        /// <item><paramref name="mainSchemaDefinition"/> contains an invalid schema definition.</item>
+        /// <item><paramref name="mainSchemaDefinition"/> is invalid.</item>
+        /// <item><paramref name="nestedSchemaDefinitions"/> contains invalid schema definition values.</item>
+        /// <item><paramref name="mainSchemaDefinition"/>, all together with its referenced
+        /// <paramref name="nestedSchemaDefinitions"/>, contains an invalid schema definition.</item>
+        /// <item><paramref name="nestedSchemaDefinitions"/> contains schema definitions that are not
+        /// referenced by <see cref="mainSchemaDefinition"/>.</item>
+        /// <item><paramref name="mainSchemaDefinition"/> does not reference the default schema definition
+        /// <c>ConfiguratieSchema.xsd</c>.</item>
         /// </list>
         /// </exception>
         /// <exception cref="CriticalFileReadException">Thrown when:
         /// <list type="bullet">
         /// <item><paramref name="xmlFilePath"/> points to a file that does not exist.</item>
         /// <item><paramref name="xmlFilePath"/> points to a file that does not contain valid XML.</item>
         /// <item><paramref name="xmlFilePath"/> points to a file that does not pass the schema validation.</item>
+        /// <item><paramref name="xmlFilePath"/> points to a file that does not contain configuration elements.</item>
         /// </list>
         /// </exception>
         protected ConfigurationReader(string xmlFilePath, string mainSchemaDefinition, IDictionary<string, string> nestedSchemaDefinitions)
@@ -137,14 +146,14 @@
         }
 
         /// <summary>
-        /// Validates the provided XML document based on the provided XML Schema Definition (XSD).
+        /// Validates the provided XML document based on the provided schema definitions.
         /// </summary>
         /// <param name="document">The XML document to validate.</param>
-        /// <param name="mainSchemaDefinition">A string representing the main schema definition.</param>
-        /// <param name="nestedSchemaDefinitions">A <see cref="IDictionary{TKey,TValue}"/> containing
-        /// one or more nested schema definitions</param>
         /// <param name="xmlFilePath">The file path the XML document is loaded from.</param>
-        /// <exception cref="CriticalFileReadException">Thrown when the provided XML document does not match the provided XML Schema Definition (XSD).</exception>
+        /// <param name="mainSchemaDefinition">A <c>string</c> representing the main schema definition.</param>
+        /// <param name="nestedSchemaDefinitions">A <see cref="IDictionary{TKey,TValue}"/> containing
+        /// zero to more nested schema definitions</param>
+        /// <exception cref="CriticalFileReadException">Thrown when the provided XML document does not match the provided schema definitions.</exception>
         private static void ValidateToSchema(XDocument document, string xmlFilePath, string mainSchemaDefinition, IDictionary<string, string> nestedSchemaDefinitions)
         {
             var combinedXmlSchemaDefinition = new CombinedXmlSchemaDefinition(mainSchemaDefinition, nestedSchemaDefinitions
@@ -170,7 +179,7 @@
         }
 
         /// <summary>
-        /// Validates whether or not the provided XML document is empty.
+        /// Validates whether the provided XML document is not empty.
         /// </summary>
         /// <param name="document">The XML document to validate.</param>
         /// <param name="xmlFilePath">The file path the XML document is loaded from.</param>