How do I reset groups?

If your groups seem to be "superadmin", "admin", "user", then it's possible that your groups may have been overwritten by the defaults of another admin mod (See here to make sure you've removed any other admin mods).

If this is the case, or if you just need to reset xAdmin groups back to the defaults, simply run this command in your server console, which will reset all xAdmin groups: lua_run xAdmin.ResetAllGroups()