E: The code execution cannot proceed because t6r/t6r.dll was not found
F: Make sure t6r.dll is in the t6r sub-folder. Usually It is missing due to your anti virus software deleting it. Once you added an exception for it redownload the client files to get the t6r.dll.
I suggest you read the thread here https://forum.plutonium.pw/topic/9/common-issues-and-frequently-asked-questions
TLDR: You need to whitelist the BO2 folder as your antivirus is deleting t6r.dll as it is mistaking it for a virus.
I did all of that and it still doesnt let me open black ops 2 ive tried turning the firewall and windiws security but nothing seems to work but when i downloaded it first it works but i accidentally closed the game and when i gave it access to run as admin it stopped working