"Credentials must not be null" when connecting to TFS server from Eclipse with TEE

Question

I'm having regular problems connecting my Eclipse workspace to my TFS server using Team Explorer Everywhere.

When I select my server in the "Add Existing Team Project" dialog, I get a dialog with the title "Connection Failed" that says "Error connecting to server: credentials must not be null"

It doesn't happen every time, but certainly more often than not. At the same time that this error occurs, I can successfully connect to the same server using Visual Studio 2010.

I have Eclipse Indigo SR2 (build 20120216-1857) with TFS plugin-in 11.0.0.201212121120 on Windows XP Professional x64 Edition SP2.

I followed the instructions in http://blogs.msdn.com/b/davidmcg/archive/2007/05/25/changing-team-foundation-server-credentials.aspx to make sure I didn't have any unwanted cached credentials (although I don't HAVE any other credentials that I could ever have used).

What does this error mean? I presume that my Windows credentials will be used to connect to the TFS server, and demonstrably this works (always, using VS2010, and on occasion, using Eclipse/TEE).

Answer 1

I have been having the exact same problem. The solution for me was to clear cache folder for TFS Client Client. They are located under:

C:\Documents and Settings\\Local Settings\Application Data\Microsoft\Team Foundation\3.0\Cache

Delete everything in that folder. There might be more than one version installed on your machine. Make sure you clean them all.
1.0/Cache
2.0/Cahce
etc...

A workaround that worked sometimes was to open Visual Studio before Eclipse. Somehow Eclipse gave less errors when VS was open and authenticated to TFS.

Here is a similar question I asked about it earlier. It was answered by a guy from TEE developer team. I bet it is worth looking: Team Explorer Everywhere warning in Eclipse