System Thread Exception Not Handled on boot with Win10 guest and opensuse host.

[Nicolai Derlich]

Hey there,

I recently updated my hosts uefi-firmware and now my Windows guests
bluescreen on boot with "System Thread Exception Not Handled". Qemus
version is 6.2, the guests are using virtio-hard-drives and the host has
an MSI carbon MB running a version of click bios 5 and an AMD Ryzen 7
1700X.  SVN is enabled on the host. Since the installation ISO produces
the same error, I'm sure it's a BIOS-setting on the host causing it, but
I have no idea what to look for. Or could it be a feature update of
Windows I somehow missed?

I can provide more info as necessary, though has anyone encountered this
error before and can give a pointers to what host/bios options it
relates to.

Thank you all in advance.