A duplication bug in 13W05B

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• Was this a single player or multi-player/lan game?

• Was the issue corrected after logging out and back in?

• Was the issue corrected after closing the program and restarting?

• Have you been able to reproduce this?

• Attach a crash report if possible.
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Try it out using this setup for proof.

No crash singleplayer not corrected for both

Please do not mark issues as private, unless your bug report is a security issue containing information that may compromise your server/client.

I made it private since is was flagged as incomplete (Sorry I am new here and I should have read the rules better.)