The TT sundering: map closed when full
It’s weird when it comes up during Guild Missions when 30+ people just from the guild are in one map. Not sure what the lower threshold is, but it’s odd anyway.
This seems to happen when you taxi people onto your map while it is in “soon to be closed” state. In this state you won’t get onto the IP by normal means, if the player count is not close to the minimum limit. By taxiing people in, the system doesn’t seem to lift the closure state, because you are essentially ircumventing the only condition the state has, namely people going there by normal means. Its a bug that happens rarely enough but is nonetheless a huge disappointment. Happened to the german Dry Top organization twice as well.
You seem to be able to prevent it by NOT filling a map with guild mates which is doomed to be closed soon. Instead search for another IP which isn’t in the state of closure.