ejer

Same here, my friend was looking at/generating a map at the time so maybe the problem with maps isn't fully fixed yet? 🤔

The same happens to me and my friends!

I'm running the latest snapshot server. (20w12a)

It looks like this is caused by the map trying to load signs in the world.

The fix is easy though, you just need to throw it out as soon as you join or switch your current slot.