We have detected the use of a third-party application in violation of our EULA. Overwatch will now exit

This message comes up every time i try to join the game, Ive uninstalled my Ge Force driver and reinstalled a different version over and over again it doesn’t seem to be the issue. I don’t have any third party applications???

This started happening once i updated to the Halloween event.

Did you ever use Visor or Pursuit? Both of these applications are in violation of the EULA. Starting with this patch, the game will shut down if it detects the files of either application. Uninstall the application(s) in question and make sure you delete any residual files in your Program Files (x86) folder and your ProgramData folder (both located in the root directory of your C Drive).