We get this on resurrection sometimes too. I dunno what causes it, but seems to be something to do with the dimension not being loaded in memory at the time (IE, noones there), and some serverside mod, somewhere, not queueing it up for load when requested. Using a regular portal to the dimension you're trying to get to fixes this, but once you leave, the dimension gets unloaded, and you have to repeat
thx i presume it will work after restart. And while we are at it. Is there some way how to automatickly give to all players achivment at least those two at start in twilight ? Bcs i am not sure but thats the only way how to track in which order i have to kill bosees to progres somehow, so they dont have those fancy protection auras and such. But i am not sure of it. Never did any research on a subject.
A new topic with a matching title might be advisable. (I have no idea, else I would have told you what I know.)