Even if your Product Key is currently not working, maybe it is working for someone else.
And if someone else knows it, and uses it, your key is in use and useless for you.

So the forum will try to block you from posting, if a text like that appears:

ASDFE - ASDFE- ASDFE - ASDFE - ASDFE-X

maybe it helps

PS: the same problem exists with Screen Shots from the Licence Tool but here this new check can not help