One day I tried to start to run my application on Visual Studio 2008 and got the following error: Unable to start debugging on the web server. Could not start ASP.NET debugging. More information may be available by starting the project without debugging.
So I clicked on Start Without Debugging as suggested and got the following error: Service Unavailable - HTTP Error 503. The service is unavailable.
This usually means that my web server is not running. I did a quick check inside IIS Manager, and found that my web site was running, but the application pool was not. I started my application pool and tried again but got the same error. I refreshed my application pools and found that it was not running again. It turns out that the password of the identity that my application pool was using had changed. I clicked on my application pool, went to Advanced Settings | Process Model | Identity to update the password to fix the problem.
