Well, first of all I have three problems, two about the game in general and DayZ: 1. I happen to buy the Arma II Combined Operations on Steam and all the downloaded and installed right after attempting to start the launcher Operation Arrowhead Arma II and left me a message saying "Bad Serial Number Given In Setup", being my original game and I started googling and found it may be that another user is using my CD-KEY and is playing like KEY stealing my style and I got really scared because it cost me to buy the game for me to come and steal the code or that, I started to do several things that were on forums to see if it fixed the problem and not managed, now I use the Arma II but if I give play from Steam, but I will address the respective path and run the launcher Arma II and OA. and I get the message "Bad Serial Number Given In Setup". 2. Install the mod DayZ and DayZ Commander and update everything, and when I want to get into any server I get the message "Bad version, server rejected connection" and not let me in to any server, and I've looked all updates of DayZ Commander and everything is updated, leave a picture here. 3. And the third and final problem is that on some servers (not all) to start the server I get the message "You cannot play / edit this mission; it is depends on downloadable content that has been deleted. Img_marine" and I can not enter some servers this server, I get this error on some servers for downloadable content and that. Without more, these are the errors that I have for not playing DayZ, thanks and hope you can help me.