Error: Sys. WebForms. PageRequestManagerServerErrorException
When trying to run a .NET web-application which uses Ajax either:
- the following error is generated in the browser:
Error: Sys.WebForms.PageRequestManagerServerErrorException: An unknown error occurred while processing the request on the server. The status code returned from the server was: 500
- Nothing appears to happen in response to some interaction on the page. (The above error is being generated if you hunt for it - either by enabling notification of script errors in IE or using the Error Console in FireFox.)
Attempt to reproduce the problem while debugging in the Visual Studio environment. The underlying error will then become apparent, allowing you to address it.
These notes have been tested within Microsoft Visual Studio .NET 2008 running under Windows Vista, and may apply to other versions as well.
About the author: Brian Cryer is a dedicated software developer and webmaster. For his day job he develops websites and desktop applications as well as providing IT services. He moonlights as a technical author and consultant.