Cannot boot Zorin vhd.vtoy file using grub2/grub4dos (but OK using Ventoy)

[steve6375]

I am not quite sure what I have done to the VHDs but I have two zorin legacy-installed VHDs which show the same problem. They were legacy booting OK previously and then I must have done something such as add grub2 uefi files and now they will only boot using the Ventoy menu system. If I use vdiskchain (either under grub4dos or grubfm/grub2) I now get a vdisk parameter not found error.

but they still both boot fine using Ventoy and they were both booting fine yesterday using grub4dos/grub2/ventoy so I must have broken something!

Can you suggest what might be wrong and how to fix please? Is code in vdiskchain same as Ventoy code?

P.S. Ventoy will also UEFI-boot from the vtoy files but it complains about not a uefi disk and also a 10 second Warning - not a Ventoy disk, but then boots OK!