How to: Debug ASP Errors with Just-In-Time Debugging
If there is a syntax or run-time error in an Active Server Pages file, the server stops the procedure that contains the error. If debugging is enabled for that ASP Web Application, the server prompts you to start the debugger and displays an error message. If debugging is not enabled for the ASP Web Application, an error message is sent to the client browser. In either case, the procedure that contains the error stops.
If a debugger is installed on the server, the server does not pass error information through to the client. Instead, it displays an error message on the server computer's monitor.
You can launch the debugger in response to an error or debugger statement only if just-in-time debugging is enabled. For more information about how to enable just-in-time debugging, see Just-In-Time Debugging.
To debug ASP script in response to an error
When an error occurs and the Just-in-Time debugging dialog box appears, choose the Visual Studio 2010 debugger.
In Visual Studio, open the project that contains the ASP file to be debugged. If the project is already open in another instance of Visual Studio, you cannot open it again. Instead, Visual Studio creates a new solution and new project.