502 web server received an invalid response while acting as a gateway or proxy server

Hello,

I have been getting "502 web server received an invalid response while acting as a gateway or proxy server" when trying to access a page and the ColdFusion is application is server is hanging up and will not restart as well.
Have you guys seen this error with ColdFusion 11/IIS 8.0 and any help is much appreciated.

Thanks in advance