VS2010 error: Unable to start debugging on the web server

Question

I get error message \"Unable to start debugging on the web server\" in Visual Studio 2010. I clicked the Help button and followed the related suggestions without success.

Answer 1

These steps my differ depending on your version of Windows. I am using 7 with iis 7.

Open IIS Manager, click on Application Pools and find the 2 ASP.NET v4.0 pools (One is called "ASP.NET v4.0" the other "ASP.NET v4.0 Classic". Chances are that first one is stopped. Do not start it yet, we need to investigate a bit more.

For the "ASP.NET v4.0" pool, check the name in the Identity Field. Is it ApplicationPoolIdentity? Remember the name.

Open Computer Management (right click on My Computer and select Manage). Expand Event Viewer, then Windows Logs. Click on Application and wait for the data to load. There should be an error with a source of User Profile Service with a message that starts with "Windows cannot log you on because your profile cannot be loaded. Check that you are connected to the network, and that your network is functioning correctly."

If you do find that, then you have the same problem as I did.

The Solution: Go back to IIS Manager and right click on "ASP.NET v4.0" and select Advanced Settings. Under Process Model, the first field is Identity. Change this from ApplicationPoolIdentity to NetworkService. Click OK.

Now start the pool if it did not restart automalically. Go back to your application and press F5 (start debug) and your application should work.

Please note that I have not figured out why this works, and this may be a security risk, but at least you will be able to do some work while you think about this.