I had that 2 or 3 times where you cannot do anything but chat.. i canceled it using the little x somewhere and got back to crafting again..
It's a point where everything freezes and no button will respond.. not sure why it happens , and i am 100% sure it has nothing to do with lag at all , since once canceled everything works as it should be + everyone around you also moves normal and do their things normal while your crafting is frozen