Unable to start debugging on the Web Server. Visual Studio 2008

debuggingiisvisual-studio-2008

I am running visual studio 2008 SP1 on Windows Server 2008 R2 Enterprise 64-bit. I am getting the following exception when I try to debug against IIS.

"Unable to start debugging on the web server. The object identifier does not represent a valid object".

IIS and Visual Studio are on the same box.

I've tried enabling Windows Authentication but no luck (my app requires forms authentication, fyi).

Any thoughts? I have a binding on the Web Site. The IIS app is a Web SIte not a virtual directly.

Thanks!

P.S
I have posting this as a new questions since the previous question I found is not answered and the solution provided in that question is not working as well.
Previous Question:
Unable to start debugging on the Web Server. Visual Studio 2008

Best Answer

When I hit this problem I opened the basic settings in IIS and checked the app pool set for the web site. It was set to "Default" and not (as it should have been in this case) to ".NET 2". Changing that setting was the fix.