CD Key In Use Problem

Right before I change my banned key to a new purchased key, I check if the purchased key is valid and not banned. The new key is valid and not banned. I go ahead and change my banned key to the new key using Darky's Key Changer. I launch DayZ through the SIX launcher and upon joining a server, it says the CD Key is in Use. Every time I change my key to a new key, I get this message, when not 2 seconds ago that new key was valid. I'm the only one using that key for sure, but it's reading that the key is in Use, and basically that key is gone because it will be forever in use.


I'm going to go ahead and just reinstall the game entirely. Maybe I need to use a different Key Changer too?
Any help? Much appreciated! thanks!

You are obviously not the only one using that key. If you bought a key from someone on MPGH, he most likely sold it to another person or the person that he stole it from is using it. Most stolen keys dont last more than a day or two, and if your seller has a warranty ask him to replace it for you.