When attempting to tab-complete a function name in the function command, the game will freeze and then kick the player if there are too many functions, yielding the following:
Internal Exception: java.nio.channels.ClosedChannelExceptionThe player is then sent to the Multiplayer screen, even when kicked in singleplayer (this is MC-45602).
Linked issues
is duplicated by 1
Comments 3
This does not only happen when auto-completing. Apparently, this also happens when opening a world with many functions. See MC-122676 (world download examples available there)
How many functions do you have? The only way I can think of this happening is if the tab complete packet that was generated exceeded the 1 megabyte limit (that packet doesn't have any maximums that'd affect this - while each entry has a max length, the total array doesn't, and you'd need several billion functions for it to overflow...).
Also, can you reproduce this with packet debug logging enabled? When that's enabled it should add a stacktrace for exceptions like that in the log.