Example:
Anvil slot 1: Power 1 Enchanted Book
Anvil slot 2: Power 1 Enchanted Book
Clicking on Anvil Slot 3 for Power II Enchanted book results in item disappearing and leaves original books in slots 1 & 2.
The enchanted books in slots 1 & 2 after the resulting book disappears become inactive in the anvil and must be replaced to show new result in slot 3.
Duplicate of MC-1907, please use the search function to see if your bug has already been submitted. Currently over 55% of tickets are being closed as duplicate.