for other software reasons my daily driver iMac still runs Mojave 10.14.6 and VM Fusion Version 8.5.10 (7527438)
and ALL my guest OS worked fine.
I also have a MacBookPro Ventura 13.4.1 running VM Fusion Player Version 12.2.5 (20904517) and am very aware that should I try to move a Guest OS from this Mac to the older, it won't work because the VM has been created with a newer version
However, I've just gone to use VM Fusion 8.5.10 (7527438) and discovered ALL my guest OS suddenly give the
"This virtual machine was created by a newer version of VMware Fusion error" error 
If I change COMPATIBILITY to an individual Guest OS setting to use HARDWARE VERSION 12, the OS will open
but one of my guests was SUSPENDED and I cannot change it or shut it down in this state
thats how I know something changed!
- why has this occurred?
- How do I close a suspended OS when I cannot open it (unless I move it to the newer Mac, close it, move it back)
...TIA