hi, Guys!
It is Great News!
Windows Update on Jan/3/2018[KB4056892] might fix this probrem!
You no longer need HackFlags nor Disable Audio Devices!

Can anyone confirm this aswel?
Hey guys, I can confirm it worked for me too. I actually used the above tips (including the registry edit) to run 5 GPU rig. Yesterday, after the update, my 5th GPU stopped working. After removing the edited registry, it works flawlessly, now even with 6 cards.