Having the "Signing You Out" issue w/ clean cache

So I am having the issue where as soon as I start a game (Campaign OR Matchmaking) it says “signing you out” and boots me to the main menu within a few seconds of having entered the game. I have seen many people say that the way to fix this is to clear the cache by deleting everything in the webcache dir however I have done this several times and it isnt working. I know its some sort of related issue because when I switch my network to LAN I can play singleplayer just fine. Problem is I would also like to play MP. Any Ideas??

Thanks
-Pinhead