DayZ mod - Cannot Play/Edit this mission

[thepigking 0]

First of all, sorry if this post is in the wrong place, I'm new to forums.

So anyway I've just got Arma II and Operation Arrowhead because they were on sale on steam, and being a fan of the standalone I thought I would install the mod. So I bought them both and downloaded them, and installed the mod using withSix_Play. Then after it's all been installed I get this error message:

 

"You cannot Play/Edit this mission; it is dependant on downloadable content that has been deleted.map_eu"

 

I have time logged on Arma II and Arrowhead, so everything is installed. Any help would be appreciated, thanks.

 

I also took a screenshot of the message.