The bug: when a player dies on a server and logs out without respawning, they are unable to rejoin the specific world they died in.

I'm staff on a Minecraft server, and a few of our players reported that they were getting stuck on the "loading terrain" screen. Some reported being able to hear audio while on the loading screen. They showed up as online for us, but were invisible if teleported to. They were able to join other worlds on the server after mods tried sending them there.

While investigating, I saw similar reports on the official Minecraft discord's community help channel and twitter support feed. None of them were resolved. One of our devs discovered the problem seemed linked to the playerdata files, and removing them let the players rejoin the worlds they previously could not. He also realized that all the players with this issue had died and then logged out without respawning.

This was reproducible by dying on the server, then returning to the main menu or quitting Minecraft without respawning. On the next attempt to join the server, the game gets stuck on the loading terrain screen.