10.12 drivers wont work with the 69xx series cards. the 69xx cards did not have drivers signed or coded with 10.12 so amd released a modified 10.11 set and called it 10.12a.
10.12a hotfix is needed. get it here.
also for graphics hardware acceleration you will need to install this too.
uninstall ALL ATI drivers and install manager in windows.
when it asks to reboot click yes.
during boot up hit f8and select safe mode.
run driversweeper and checkmark ati - display as your filter and hit clean.
it'll ask you if your.. click yes. then click reboot later. and run sweeper again by clicking clean. click yes and reboot.
then boot back into normal windows and install 10.12a. don't reboot and install opencl grapchics hardware acceleration drivers and reboot one last time.