@Technogeezer wrote: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.
I follow what you are saying thank you.
But why has ALL my guest OS suddenly changed to thinking they have been created on a newer version? (when they haven't).
It has always run fine on this computer until now. It's just a pain to have to select compatibility on each OS (a 4 step process) as I have 21
@RDPetruska note to remove vmss worked great, thankyou. Once removed I then had to change the compatibility, but at least it now opens.
