Currently helping the managing ATM6 Sky, some players in multiplayer are reporting not being able to create or join a team even on a new world as it says "Already in a Team" no matter what commands used to leave or create a new team. Not sure if this is a recently fixed issue or not but I can reproduce it as well

Formatting from players incorrect

Okay.. which version do you/they use?
If 1.6.1, I just found the problem and will fix it later today.

Ok second look, it seems that a real called spawn is created at start and doesn't allow anyone to join or make a team until that fake team is deleted