I have/had the exact same problem, I had installed AMD drivers 15.7 . i uninstalled the drivers and then installed the old AMD 14.12 and action! worked perfectly.
Mirillis!! , I have 2 x PC , 1 x Win 7 home and 1 x win 8.1 pro , Action! has stopped function on both since installing AMD drivers 15.7
programs starts and I can see it processes in task manager , but Action! does not work. tried reinstalling Action! , no help
Odd . my AMD APU 5800k with 7660D , Action! supports AMD APP. 7660D is a VLIW4 design , so is the 6900 series. I've also used HD 6670 card in CrossX with APU and AMD APP worked very well in Action! I also mucked around with putting a 5850 in the same PC ,AMD APP didnt work, I had to re-install Actio...