If anyone wants to participate in the community action, visit https://save.tf and sign the petition against botting (we’re almost at 230,000 signatures) and/or post about it on the social media site of your choice. #FixTF2 :)

Very good tip, this was also the issue on an old desktop of mine. For 3 years I thought it was just cursed until I finally removed and reinserted the RAM sticks. Now it works flawlessly!