When I try to start a VM on macOS Monterey 12.0.1 RC I get
Transport (VMDB) error -14: Pipe connection has been broken
This is what happened when trying to run a VM in Fusion 12.1 on Monterey beta.
Fusion 12.2 worked on Monterey beta 10, but does not appear to work after an upgrade to the 12.0.1 release candidate.