Groups not showing up on the Player List

Hey I used to be able to see people ranks with the TAB button. I went to a player controlled/purchased(in game monetary units) ranking system and permission but I dont see their groups in the Tab .. I see them in the database. Is this a setting in serverproperties or the permissions?

This happens when you have corrupt permission files. They may look ok but if there is a tab in the mix or some other issue that is not YAML then they will not give you an error. They will just not be used.