I have the same problem with an AMD Radeon Pro W6600, now here’s something interesting I was running my system on a threadripper 1950x X399 and i just moved it to a TRX40 with a 3960X both slots directly connected to the cpu, Gen 4 X16 same installation same boot drive was working fine on X399 but refuses to work on TRX40, just keep getting Error 43 over and over. I’m on the latest version of Dragonfish.