WinHost and SCO OSR6 works in VBox6, fails in Vbox7

[MarkBen]

Good morning, My office has run VBox (vs VMWare) for nearly a decade, issue-free.

HOST: Current host OS is Server2019 but cannot upgrade from VBox6.1.42 to ANY VBox7.x. Problem can be duplicated on host Win10.64 (source of attached log.zip).

Virtual OS is SCO Unix (OSR6DM1, fully licensed, patched). I posted my issue on VirtualBox.org in this (short) thread:

​https://forums.virtualbox.org/viewtopic.phpf=6&t=109006&p=534055#p534055

I've included a log.zip that's also on that thread, and 'scottgus1' pointed out this from the log file: 00:00:44.916247 virtioNetR3Ctrl: Unrecognized CTRL pkt hdr class (80) 00:00:44.916297 virtioCoreVirtqAvailBufCount: Driver not ready 00:00:44.916607 virtioCoreVirtqAvailBufCount: Driver not ready 00:00:49.198793 Changing the VM state from 'RUNNING' to 'GURU_MEDITATION'

"Looks like maybe the virtio system is having trouble? Try reverting to 6.1.42, see if the VM comes back."

I can uninstall VBox7.x (either Win10 or Server2019), rollback to 6.1.42 and SCO Unix runs just fine. I've even tried fresh SCO installs over the weekend, tried changing #cores, RAM, deferring network setup (Bridged | paravirtualized(virtio-net)= 6.1.42 settings) etc to no avail. As soon as the install is completed and system reboots, SCO has a kernel-panic and immediately shuts down.

If there's anything else you'd like me to try, I'm willing to help address this!

Respectfully, MarkBen Mark Benavides, DDS Ottawa, IL