Moderators can't see link to MOD CP
 

My moderators can't see the link in the footer to the Mod CP, they also don't have any ban permissions. I was trying to find where I can set who has permissions to the Mod CP and who can ban but I can't find it anywhere. Where did I go wrong?

I have my users set as Moderators for their primary group and registered users as their secondary group. Should they only have one group assigned?