Plutonium

I have a problem from my friend,so my friend can't not join me for no reason. so i tried to invite him,and it saids error again. if i join him session it saids a error too,can someone help me- or it is a bug,we restarted our pcs and still the same. we had no idea,so we did restart the game and restart the pc and still NOT Working. it's a impossble i wanted to play custom games. not server browering.

Resxt i never played windows and yesterday was my first windows playing
very sorry but no help for it. my friend fixed it.

So. I putted the BO2 Full Game And i have the Plutonium Updater when i cilck "Setup" the bo2 full game i cilck it and accept it,and its still setup. and i tried to delete it and over again and again, i don't know what to do