Getting 'unable to start debugging' 'An authentication error occurred while...'

Question

This sure seems like a simple error to fix. However, I somehow can't figure it out. Found some posts here and went thru them and couldn't get it to work. Sure seems like a famous error.

The error I'm getting is : Unable to start debugging on the web server. An Authentication error occured while communicating with the web server.

I'm running VS2k8 on the Server 2k3sp2 web server. I've verified debugging is set in the web.config and verified http keep alives are set in IIS. I've set the web to run using integrated authentication. I've even tried to attach to the process. However, my breakpoints say that running code and current code doesn't match, even though I compiled the web and ran it..sounds like im attached to the wrong process but there is only 1 w3wp process there to attach to, which should be just my process.

I even did an aspnet_regiis. Still notta.

Thoughts?

Answer 1

Make sure to check that in IIS, the authentication mode is set properly. If you're on a Domain, make sure to note such, and make sure that Anonymous access is checked (if required for your application).

This MSDN Link has more details.

There are a few other things you can try as well:

• IIS 7.0 Debugging Hotfix
• IIS 7.0 Issues
• Other things to Try

Let me know how that works out for you.

Answer 2

After looking around, I noticed there were 537 - 'An error occurred during logon' security events every time i tried to launch in debug mode. I found this article on M$-

http://support.microsoft.com/?id=896861

After setting a key in the reg to disable the loopback check per the article and a reboot, problem solved! Since it's a dev box on the inside, shouldn't be a security risk.

Thanks for the help!!!