I also get problems when trying to install the blockchain driver on my RXvega56, windows 7. I am using CSM (compatability select module) instead of UEFI bios, and have a multi-boot OS. I have 4 OS partitions. 1st I leave alone, 2nd I tried with blockchain. I am logged into the 4th OS while the 3rd has a windows 10 customer improvement build (or whatever they call it).
I will attempt to install blockchain drivers on 4th but, it gives me that problem where on reboot there is no display until u get to windows. So if I had on 1 OS I would be reinstalling it right now!