14.3 and 14.2 crash. 14.1 works. Any advice?

14.1 works, 14.2 and 14.3 all crash when loading both from "adding to queue" or direct launch.

I can export from Premiere Pro directly.

I have reloaded several times and full system shutdown and relaunch.

Most recent Adobe CC installs of everything.

iMac Pro (2017)
3.2 GHz 8-Core Intel Xeon W
64 GB 2666 MHz DDR4
Radeon Pro Vega 56 8 GB

Catalina 10.15.6

Any advice?

thanks

Craig