The bug
Entering or leaving the nether results in the player getting kicked with the message "Timed out", then placed at the entrance coordinates in the other dimension.
This only happens when running a dedicated server - not in singleplayer.
Related issues
Comments
migrated
pokechu22
I can still reproduce this without going into multiple portal blocks horizontally (i.e. I stand at the edge of the portal, while I'm assuming "Note: You must be standing in 2 portal blocks at the same time to recreate" meant that you'd need to send in the center). Can't reproduce getting stuck in an infinite loop, though I did have it where I got kicked immediately on join.
Here's a snippet of the end of a debug log:
[21:03:27] [Netty Server IO #3/DEBUG]: OUT: [PLAY:26] iy // this is a kick packet
[21:03:31] [Server thread/INFO]: pokechu22 lost connection: Timed out
[21:03:31] [Server thread/INFO]: pokechu22 left the game
[21:03:32] [Server thread/WARN]: handleDisconnection() called twice
Creeperlover2001
Can confirm. This bug also has a chance of sending you in an endless "kick loop", which somehow kick you every time you try to log back in the server. To fix this, the victim has to be teleported away, and even then, it sometimes doesn't work. The best solution we found is to teleport the person in an End Portal.