It is a duplication glitch that does not crash the game.
MC-9254
A duplication bug in 13W05b
Resolved
Duplicate
0
David Browning
(Unassigned)
Unconfirmed
Snapshot 13w05b
Retrieved
36th Duplicate of MC-8198, please use the search function to see if your bug has already been submitted. Currently over 51% of tickets are being closed as duplicate.