If your ''Hotbar'' is full and you try to ''shift+click'' an item it will disappear.
The same thing will happen if you'r looking in a chest and ''shift+click'' an item with a full inventory.
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migrated
MC-89036
Disapearing Items 15w38b
Resolved
Duplicate
0
migrated
migrated
(Unassigned)
Unconfirmed
Minecraft 15w38b
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Thank you for your report.
However, your ticket has been resolved as a duplicate.
This issue has been linked to the original bugreport: MC-88929. You can find or add further information on that report.
Please search before reporting any bugs, as it's likely that one exists already.