How to solve problem, An exception occurred while processing your request. Additionally, another exception occurred while executing the custom error page for the first exception. The request has been terminated.

When saw this error, go to web.config file, disable the customer error. Then you will see the real error.   Set to RemoteOnly if in the production environment, so only real error in local.
<customErrors mode="Off" >


Reference
http://msdn.microsoft.com/en-us/library/h0hfz6fc(v=vs.85).aspx