Sending an item_crack particle will disconnect clients with a server-side IndexOutOfBounds exception.

Debugging this a little, it appears that particle now takes a two-dimentional array of material id/durability, rather than a single combined integer.

This is my suspicion, because if I send a raw packet formatted like that (2D data array) it does not cause an error and shows the correct particle, even for items like colored wool.

I am confused by this, however, because looking at the mcserver code it doesn't seem like it actually does this internally (see: EntityLiving, the only use case I can see for this particle). I may be misreading something there.

This bug is easy enough to reproduce, just put this in a PlayerInteractEvent handler:

event.getPlayer().playEffect(event.getPlayer().getEyeLocation(), Effect.ITEM_BREAK, Material.DIAMOND_AXE);

I checked for duplicate issues and found only SPIGOT-7 which appears old and due to user error.