PRB: "Unable to Start Debugging" Error Message When You Send Debug HTTP Request


When you debug an ASP.NET application in Visual Studio .NET, you may receive the following error message:
Error while trying to run project: Unable to start debugging on the web server. Server-side error occurred on sending debug HTTP request.

Make sure the server is operating correctly. Verify there are no syntax errors in web.config by doing a Debug.Start without debugging. You may also want to refer to the ASP.NET and ATL Server debugging topic in the online documentation. Would you like to disable future attempts to debug ASP.NET pages for this project?


This problem can occur if there are syntax errors in the ASP.NET application's Web.config file.


To resolve this problem, make sure that all of the Extensible Markup Language (XML) in the Web.config file is valid and well formed. Also, remember that everything in Web.config is case-sensitive.

Article ID: 306163 - Last Review: Mar 24, 2009 - Revision: 1