FIX: Sign in as a Different User in SharePoint 401 Unauthorized Error Fail

The problem:

You login to Sharepoint (WSS or MOSS), then click the “Sign in as a different user” drop down. You attempt to login using the same account with the same privileges (obviously) and for your efforts, you get a 401 Unauthorized message. What?

The fix:

DON’T USE THE SAME ACCOUNT!

Seems rather intuitive, although the error message is not. “Sign in as a different user” really does expect a DIFFERENT user. In testing mode, it’s common for developers to test and retest using the same account. Why not? Sign in as Admin, then attempt to relogin as Admin. We’ll that’s a big fat no-no.

Incidentally, the same is NOT true for a simple Sign Out. Assuming you are using FBA, you can log right back in using the same account.

Hopefully that saves some hair pulling.