Connect to TFS error TF31001 object reference not set to an instance of an object

Question

I have a user running VS 2015 trying to connect to our on premise TFS 2015 U2 environment. Other users are able to connect but this user is receiving the following:

Object reference not set to an instance of an object when trying to connect to the TFS instance. Won't even list the collections. I've verified he can ping the server, he can open tfs web access in IE. Any idea why this is occurring or what log I can look at on his machine that would provide more detail?

Solution 1

1. Try to clear the cache on this client computer:

   • Close any open instances of Visual Studio.
   • Browse to the following folder: C:\Users\username\AppData\Local\Microsoft\Team Foundation\6.0\Cache.
   • Delete the contents of the Cache directory, including all subfolders.

2. Disable the antivirus software or firewall to determine whether that change corrects the problem.

3. Use the IP address of TFS instead of server name if you have used server name.

Solution 2

One of the most possible cause is your tfs server machine running out of space.

Comments

[EmanP]

I tried the steps and it didn't resolve my issue. My next thought was eliminate the user profile being a problem, so I ran VS on the users machine as my user, VS set up my profile for the first time and I was able to connect without a problem. I subsequently launched VS under the users profile and it connected successfully. Completely nonsensical or I'm just not understanding the correlation but its working now.

[ckkkitty]

This was our cause. Freeing up space worked for us.

[llessurt]

I closed Visual Studio and it worked when I reopened it.