Windows 10 1803. AtiFlash 2.77 didn't work. No errors at start. But in the event viewer it's error on driver that AtiFlash use for work.
It's atidgllk.sys
On latest 1803 this driver can't be loaded by AtiFlash.
I have this error with that driver on Windows 7 64bit 7601 with AtiWinFlash 2.84.. And it hangs after the message that flashing is ok (sometimes it even doesn't appear). But! Somehow the flashing works! I just have to reboot via power or reset button. And just one time today it even didn't hang!!

So, does it mean that this driver isn't needed to flash? I think I'll try AtiWinFlash 2.77 today..
Update: my bad, that is just a 32bit driver and thus is blocked.