No bootable medium found starting linux guest after cloneVDI with compact

[SDGumby]

Had Linux Linux Ubuntu 64-bit with rather large guest 32Gb VDI with snapshots 800Gg.
Used cloneVDI v4.01 to compact drive copy VDI+snapshots(from current State) to a VDI file of about 106Gb.
Linux guest will not start, FATAL: no bootable medium found ERROR after seeing 6.1 Linux splash screen.

Also tried consolidated snapshots to o a single VDI file with the clone feature in the virtualbox manager. This image worked well but was almost 500Gb,
Again I tried cloneVDI to make a more compact copy of the working 500Gb VDI. Again it copied to about 106Gb.
Same problem. Image would not boot, FATAL: no bootable medium found.

Storage for VM configured for SATA controller with a dynamically allocated storage for normal VDI format.

[mpack]

This usually means that you didn't have the "Keep UUID" checkbox ticked.

Some Linux installs use GRUB to select a boot drive based on drive UUID. If you clone the drive without preserving the UUID (even in the physical world) then the boot will fail.

IMO it's better to modify the GRUB script to select the boot drive by other means, i.e. hardware address.