"failed to join any instance"

Entered mud flats in phrecia event.

Went to monastery. came back. tried to enter flooded depths. "failed to join any instance.
close game. reopen. same thing. try to enter fetid pool. same thing.
try to make new mud flats. same thing.

Exactly the same here.

Did not go to monastry but otherwise the same. tried server change but it did not help either.

Same here. Restarting did not help.

Created a new "The coast" after switching gateways at login. was able to make a new instance.