What went wrong?
If standing near a port/door to another zone and you open the crafting window and attempt to drop the item into the crafting window your character will zone into the next zone if the mouse pointer is over the portal/door when you drop the item into the crafting window.
Upon zoning into the next zone you will have the item icon stuck on your screen and it will not go away until you log out/in. Zoning does not resolve the issue. See attached image.