@DatBomber420 It's not that hard to understand. Plutonium used to support pirate copies from the past. However due to the threat of cease of desist, they decide to remove support for it so Plutonium can be kept alive. BOIII a black ops 3 client was shut down, xlabs a client for mw2 ghost and advance warfare was shut down, another client sm2 for MWR was also shut down.
We discourage pirate copies to ensure plutonium survival. Or else you wouldn't even be here on plutonium complaining about why there's no safe way to play these old cods. Even if the admins put harsh restrictions, the community will complain about every possible detail. To piracy, to owning, vpn, anticheat, patches, the game, brand, features, functionality, reliability, modding, etc. At least be grateful for the things you have atm. Just don't go complaining when it's gone.
You just won't receive any support for pirate copies. It is possible for plutonium to work with pirate copies of the game. Good for you that you say own it. However on our end, we don't see the normal generate path that steam gives you. Yes, you can change the installation of the game. However, if you at least tried to verify it with a retail dvd copy or a screenshot of steam library would be much easier instead of arguing and yapping that you own the game but deny to show any prove or evidence.
When I help people, I prefer to know if they own a real copy first. Cause most of the issues here on the forums are usually people not owning the steam version, not having directx, not being able to install correctly, getting banned, having issues installing files etc.