It was suggested for me to upgrade my drivers for my 2x6700 cards with crossfire to get a Beta game I am playing to work properly. Admittedly, I don't think I have ever updated in the 4+ years of owning my PC.
So I used the tool here at AMD to detect and upgrade my drivers, which I believe updated them to Driver Packaging Version 15.20.1062.1004-150803a1-187669C and Catalyst Version 15.7.1
It did correct my issues with I was having in the beta game, however I lost my 2nd monitor, which was plugged into card 2. Now, my PC or the Catalyst Control Center will not detect Monitor 2.
I tried the Crimson Driver 16.2 or 3, that didn't work either.