friend is added but still cannot play with him

[MrMorningstar666]

i have added my friend in bo2 plutonium and i try to join him when he is paying but still i cant join, Please suggest me if there is any way i can play zombies and multiplayer with my friends in custom games. Thanks in advance

[Dss0]

MrMorningstar666 your friend/the host may have to port forward, check this guide: https://forum.plutonium.pw/topic/7/custom-games-with-friends