If none of the above works, just start from scratch. Delete the game directory, backup the 1csoftclub folder or just save your controller config and then do a clean installation of the game.
I had to do this after trying an early beta patch as performance went down the toilet and steams integrity check or deleting cache etc. would not fix it.
Edit: Ooops completely missed the second page, well if it's not a driver issue then try reinstalling the game
