If you right-click a fish bucket onto stairs or slabs, it will put the fish there, but you still have that same item in your hand.

We are unable to diagnose your issue due to the lack of proper debug information. Please review the guidelines before reporting issues.
In case of a game crash, please also attach the crash log from [minecraft/crash-reports/crash-<DATE>-client.txt|http://hopper.minecraft.net/help/guides/finding-minecraft-data-folder/].

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