NullPointerException while ticking entity [FML 8.0.9.1016+]

[14mRh4X0r]

Happened on my server on two separate occasions, once while running FML 8.0.9.1016, once while running Forge 11.14.0.1248 (both with vanilla clients).

Crash reports: https://gist.github.com/14mRh4X0r/a21217ca26694e223f93

[14mRh4X0r]

Line 221 of the vanilla EntityPlayerMP seems to be

this.playerNetServerHandler.sendPacket(new S13PacketDestroyEntities(var2));

[LexManos]

This should be impossible to do considering your player isnt added to the world until you login and the handler is set, and that happens on the world thread so there shouldn't be any issue of concurrency.
See if you can find a way to reliably reproduce this.