I'm having the exact same issue. I run steam on a MacBook Pro and decided to see if I could figure out the issue.
So I logged in to my account on my friend's HP and discovered I could use my weapons pack dlc on his computer however could not use it on my mac.
I'm not sure if this helps anyone in figuring out what the problem is.
So I logged in to my account on my friend's HP and discovered I could use my weapons pack dlc on his computer however could not use it on my mac.
I'm not sure if this helps anyone in figuring out what the problem is.