[kubuntu] Sudden fatal error when running any VM with QEMU-KVM

I'm running KUbuntu 20.04 as the host, and since yesterday, I'm getting the following error when attempting to start any VM I have set up.

https://imgur.com/P8zk50N

Up till now, everything worked fine. I've rebooted the system (Windows got me started doing THAT!), and noticing the "permission denied" on accessing
the kvm kernel module, I checked to be sure my user account was still a member of the "kvm" group.. It was. The only thing I could think of, was the
fact I wanted to test a flash drive I made yesterday to install OS using the Ventoy package on the flash drive. I ran "sudo kvm -hdb /dev/sdc" and it booted
the Ventoy menu. I didn't try running any vms then, until today. That "permission denied" appears to be a "smoking gun", but other than being a member
of the "kvm" group, I'm lost..

Thanks
Dave