An unhandled win32 exception occurred in w3wp.exe IIS Worker Process Stopped working

I am using cpp dll in my application. while calling the cpp dll in my application it leads to "An unhandled win32 exception occurred in w3wp.exe IIS Worker Process Stopped "

My version details are:

Mysql server database
.net framework 4.0
IIS7

windows server 2008

can any one please tell me why this error is raised in my application.

thank you..........