Same problem (GIGABYTE Z170X Gaming 7 rev 1.0), happened after installing Creators Update for Windows 10 (build 1704). My CPU fan speed curve isn't working anymore.
When I try to launch SIV, I get the message "EasyTune Engine is re-starting. Please wait..." but the message never goes away.
If I open "reliability history" in Windows 10, it indicates that EasyTuneEngineService has stopped working.
The motherboard itself is good but GIGABYTE utility software is very poor quality, enough to make me look elsewhere next time.