@havinabubble wrote:for other software reasons my daily driver iMac still runs Mojave 10.14.6 and VM Fusion Version 8.5.10 (7527438)
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
- why has this occurred?
It's not the version of Fusion specifically that is the problem, it's the virtual hardware version that the VM is configured with (exposed by the Fusion GUI in Settings > Compatibility). Fusion 8.5.10 is a minor update to Fusion 8.5, which supports a maximum virtual hardware version of 12. Fusion 12.2 creates virtual machines with hardware version 19 by default. Fusion 8.5 has no knowledge of virtual hardware version 19, so if you try to open any VM that has that virtual hardware version, it throws the message you see.
The best practice (that will give you the best chances for success) for moving virtual machines to a lower version of VMware products is to first shut down the VM - do not suspend - and remove all snapshots. Even better is to downgrade the virtual hardware version through Settings > Compatibility before moving it.
Moving suspended VMs makes it difficult to downgrade without manual intervention such as what @RDPetruska notes, as the "Compatibility" of a suspended VM can't be changed through the GUI.
