VisualStudio 2015.1 Enterprise/TFS integration worked fine until VS2015 update 2 was applied.
Reinstalling/repairing VisualStudio didn't fix the issue, keep getting:
TF205020: Could not connect to server ...... The server returned the following error:
Could not load type Microsoft.VisualStudio.Services.WebApi.Utilities.UserAgentUtility' from assembly 'Microsoft.VisualStudio.Services.WebApi, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.
SETUP:
VS Enterprise 2015.2 TFS 2015.2