After installing VS 2015 on my machine, when i was trying to connect to TFS from Team Explorer, i was getting the below error message: The “Team Foundation Server Provider Package” package did not load correctly.

As mentioned in the error pop up, i had a look at the ActivityLog.xml file in the path mentioned in the error pop up i.e. “C:\Users\<UserName>\appdata\roaming\Microsoft\VisualStudio\14.0”.
Scrolling down to the most recent entry in that file, i found a GUID as shown below:

To fix this issue, i opened regrdit.exe and traversed through the below path HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\14.0_Config\Packages and searched for the GUID which I found in ActivityLog.xml file.

I found the GUID entry and deleted that entirely.
NOTE: Please export the entry before deleting it to be on safer side.
After deleting the entry I restarted my machine and after that I was able to use Team Explorer.
Hope it helps !!