from looking at all these posts and from my experiences with the problem, it seems the error is when you drop the potion on your 2d character in the inventory window, that you dont properly drop the potion off your cursor or something, because occasionally i will click on another stack of potions after i have used a potion and it will add one to the stack as if i was holding one, but my cursor didnt show one as i had just used it on myself, and occasionally when i get done with the battle and i just got done using a potion, if i click on the 3d environment it drops one as if i was holding one in my cursor when it didnt show one on my cursor