I have tried numerous options, to no avail. The most I ever accomplished was changing the time of when I was kicked from the game, from in the middle of loading the mission to when I load into the game and being able to look around for a few seconds. I did this by allowing the battleye service to use all ports in McAfee firewall.

I moved my hard drive to a lesser computer to a greater one that can actually run the game decently, and the files are on an external disk drive. After moving them, most of my addons were corrupted and the game had to redownload them. So I tried to play vanilla and discovered I was kicked from all BE servers because of BattlEye not wanting to respond to them. I have uninstalled a number of programs and done numerous things.

I have tried to verify game cache, but apparently verifying is broken. At first, it was stuck at 0%. Then I cancelled it and tried again, and now it instantly completes regardless of there being missing files or not...

I simply cannot play the game at all on multiplayer until this is fixed