I started off my week in Visual Studio like I usually do, opened up VS08, got the latest code down from VSS, compiled it and started the server to try to reproduce a bug I was working on. Sounds normal right? Well, I was not-so-welcomed with a message from VS saying it was unable to start debugging on the web server cause it was not configured properly.
I did what any self respecting developer would do, I Google'd for an answer. Except the regular fixes weren't working for me! No matter what I Google'd I coudn't find an answer, until my second cup of coffee when I decided to take a different angle of attack. But first, here are some of the links you should try before doing anything else.
Tim Huffam - ASP.NET 2.0 error: Unable to start debugging on the web server
Ryan Farley - Unable to Start Debugging on the Web Server
MSDN - Error: Unable to Start Debugging on the Web Server
All of these postings have two things in common, check the application settings in web.config/IIS or check the version of .NET IIS is currently using (or thinks it should be using).
However, none of these helped me out, I was still facing that nasty error message and nothing I did was getting me any further. Until my second cup of coffee then I had a brain storm! Ok, it won't sound so BRILLIANT not, but it was for a Monday morning OK?! :> I did a CTRL+F5, started the server without debugging. Just then, I saw it! There it was staring me in the face, I didn't have security permissions on the ASP.NET temporary files directory.
Late Friday afternoon I started doing some clean up on my HD and decided to delete some temporary files which I didn't think I needed. In doing that, I deleted and then recreated the following directory.
%SystemRoot%\Microsoft.NET\Framework\versionNumber\Temporary ASP.NET Files
Deleting it cleaned things up for sure, but when I recreated it (I have a .bat file doing this for me) the mkdir didn't setup the Security Permissions for the IIS_ISRS group. Once I set that up, I was back in action! :>
Mike Volodarsky - Where did my IIS7 server go? Troubleshooting 503 "service unavailable" errors (search for 'December 4', look for Mike Volodarsky's entry on that day)