It seems that a lot of GPU problems revolve around specific versions of drivers. Though AMD has their own support structure, you can often learn from information reported by others who fold.
Im using AMD Crossfire HD7950 + R9 280 with 2 FAH GPU cores.
With FahCore_17 there was a problem when watching Videos with Player using HW acceleration: The driver e.g. 14.12 crashed!
With FahCore_18 the problem seems solved!