Sometimes crafted items disappear.

How to reproduce:

• have a full inventory
• must contain a stack of items that will be crafted
• this stack must contain less than 64 of the items to craft (number depends on the max size of the stack)
• craft so many of the items at once, that they would usually not all fit in your inventory

Now all your crafting resources will have been used and your stack is full, but some items are missing because they didn't fit the size of the stack.
I hope you guys got my point.
This is SO annoying please remove it as soon as possible.