On a multiplayer server, when a player head on top of a noteblock has a custom sound, all nearby players are kicked from the server when it is played.

To reproduce

Run the following two commands:

/setblock ~2 ~ ~ minecraft:note_block
/setblock ~2 ~1 ~ minecraft:player_head{note_block_sound:"minecraft:ambient.cave"}

Then right-click the note block. If you are on a multiplayer server, all players who could hear the sound will get kicked with the error message:

Internal Exception: io.netty.handler.codec.EncoderException: java.lang.IllegalArgumentException: Can't find id for 'alo@537879d9' in map Registry[ResourceKey[minecraft:root / minecraft:sound_event] (Stable)]

Note that when in a LAN world, the host does not get kicked.