--- a
+++ b/Interfaces/+APUnitTestFramework/DependencyErrorEventArgs.cs
@@ -0,0 +1,45 @@
+using _3S.CoDeSys.Core.ComponentModel;
+using System;
+
+namespace _3S.APUnitTestFramework
+{
+    /// <summary>
+    /// Event arguments for the <see cref="Testbed.DependencyError"/> event.
+    /// </summary>
+    public class DependencyErrorEventArgs : EventArgs
+    {
+        /// <summary>
+        /// For internal use only.
+        /// </summary>
+        /// <param name="exception"></param>
+        /// <param name="requiredInterfaceType"></param>
+        /// <param name="specificTypeGuid"></param>
+        public DependencyErrorEventArgs(ComponentModelException exception, Type requiredInterfaceType, Guid? specificTypeGuid)
+        {
+            Exception = exception;
+            RequiredInterfaceType = requiredInterfaceType;
+            SpecificTypeGuid = specificTypeGuid;
+        }
+
+        /// <summary>
+        /// Gets the exception that has been thrown by the Component Model implementation while
+        /// attempting to resolve the dependency (most likely a <see cref=
+        /// "NoInstanceForInjectionException"/>).
+        /// </summary>
+        public ComponentModelException Exception { get; private set; }
+
+        /// <summary>
+        /// Gets the required interface type of the dependency that could not be resolved.
+        /// </summary>
+        public Type RequiredInterfaceType { get; private set; }
+
+        /// <summary>
+        /// Gets the specific required type GUID of the dependency that could not be resolved (in
+        /// the case that the dependency has been marked with the <see cref=
+        /// "InjectSpecificInstanceAttribute"/> or the <see cref=
+        /// "InjectSpecificTypeInformationAttribute"/>). This property value is <c>null</c> if
+        /// the dependency is not bound to a specific type GUID.
+        /// </summary>
+        public Guid? SpecificTypeGuid { get; private set; }
+    }
+}