This exception signals an attempt to access a Type that has been unloaded.

public class TypeUnloadedException : SystemException {
// Public Constructors
   public TypeUnloadedException( );
   public TypeUnloadedException(string message);
   public TypeUnloadedException(string message, Exception innerException);
// Protected Constructors
   protected TypeUnloadedException(System.Runtime.Serialization.SerializationInfo info,
        System.Runtime.Serialization.StreamingContext context);
}

Hierarchy

Object Exception(System.Runtime.Serialization.ISerializable) SystemException TypeUnloadedException