I took a break for a day. Then I started another OS install only to be met with the same problem. I took my case apart and removed everything except the DVD drive and one hard drive. The installation succeeded. The problem was with my KVM switch which functioned at the start of the several attempts but failed later into the installs. Who knows why. It had never failed during normal operation. It’s in the garbage. More keyboards, more monitors, more cables, but everything works.
Thanks to all for the help.