The Joke Closure was a brief period in the history of the dogelore discord in which baal, an administrator of dogelore pinged everyone with a funny image in the announcements channel and the server was closed down for about 14 hours.
Many users were scared of the server being potentially deleted, and it being a deliberate nuke plan. The server was not nuked and everything returned to normal after the 14 hour time period.
A certain user made a temporary replacement server that amassed over 5 boosts and about 150 members.