Getting "Wrong CD Key" when trying to install this update

[ahmedghazi 10]

i have ArmA 2 Operation Arrowhead (steam) 1.52. when trying to install this update 1.54 getting "Wrong CD Key". how to fix this problem !!!!

[Noraf 0]

update it via steam i guess? should autoupdate, you shoud NOT download the patch from bis pages ( it even sais that on the site, that it doesn't work with steam )

If you got the patch from steam, then it shouldn't be a problem, since it should autoupdate