/* Below line writen for raise run-time SystemException::Exception */
//-------------------------------------------------------------------
object rnd;
rnd = new System.Random();
foo(rnd); /* foo has one object type argument.
* but foo will type conversiton to o paramater
* System.Text.Encoding its not possible and
* throw SystemException.*/
//-------------------------------------------------------------------

and now trying in catch block and show ExceptionForm;

mmAppBase.Log.WriteException(e);
// Display the Exception form /*its parts of your sample code.*/
mmExceptionForm ExceptForm = new mmExceptionForm(e.Message, e.StackTrace);