Plutonium

when i try to load up BO2 multi or zombies it gets stuck on a black screen with a blue loading ring going round and round. ive checked the files which come back 2 files cant be verified but they are config files i believe so they cant be verified, I've reinstalled bo2 and plutonium, my gpu drivers are up to date and my windows are up to date but i do have a preview update but don't really want to install it just in case of bugs. ive only just installed plutonium in last 2 days which was working fine but i was on multiplayer then clicked on zombies which loaded fine but when i clicked back on to multiplayer it now doesn't load both of them. so any help would be great.