No, that is the exception dialog the debugger pops up when an exception occurs, your code doesn't handle it and the debugger is running. Your end users won't see this. This dialog, coming from the debugger, is not customizable.
Your code is an MVC method. Your end users will get an Internal Server Error page which you do have control over. However we do not provide support for MVC in the C# forums. Please post your question in the ASP.NET
forums.
Michael Taylor http://www.michaeltaylorp3.net