Install kernel panic at apple logo screen

I'd appreciate some help with an install problem. System is ASRock Z97 Pro4 with an i5.

I used UniBeast, UEFI mode, no graphics injection. UEFI is set up as recommended on my system. I get repeated panics just as the progress bar begins to move on the black screen with the Apple logo.

So far, I have:

Redownloaded Sierra from the App Store
Used a different USB stick
Tried a different target drive for installation.

Help me Tonymac Kenobis, you're my only hope!...

Install kernel panic at apple logo screen