When you finish crafting an item, if you hit the "Make more X" button fast enough, sometimes the display in the crafting window becomes offset to the right. This can even go so far as to make the "Make" button be unavailable, and occasionally to leave the window completely blank.
To reproduce, craft an item and hover your mouse over whether the "Make more X" button will appear. In order to click the button fast enough to cause the bug, it may be necessary to click in anticipation of the button appearing, rather than wait to actually see the button to click.