Hi M_Saeed_Chamman,
This exception is a general exception, so we need more information about your scenario.
Could you please let us know your MapSuite version, and whether you are using anyone of our sample?
I think you can try some simple sample first here: http://github.com/thinkgeo
And please let us know your OS version and whether you are using IIS or under debug mode.
More detail information is helpful to make sure where is the problem.
Regards,
Ethan