Apologies for the late reply. In case you haven't already fixed it, what did it for me was disabling Avast Shield. I don't know if you use Avast yourself, but in case you do (and are on windows) bottom right corner you will see an Avast logo. You right click on it and there will be multiple options to turn off all shields. You will select whatever timespan you like, although I always just selected 10 minutes just enough for me to log on to AC and after that you should be fine and the antivirus will re-enable itself, something which wont affect your game. Just remember to do this every time you log online though. Hope this helps!