I am running a TrueNAS Mini X+ at some of my clients.
Today I decided to finally migrate from CORE to SCALE by selecting a different update train.
Unfortunately, after the installation and the reboot I get this error:
Welcome to GURB!
error: no such device: 1234132431241324123bc.
error: unknown filesystem.
Entering rescue mode…
grub rescue>
is there a simple trick I am unaware of?
Or should I just create a SCALE stick and reinstall?
Could not wait any longer.
Reinstalled TrueNAS und restored from the backup.
We recommend either upgrading to 24.04 using the upgrade train and then proceeding to 24.10 from there or just fresh installing with a 24.10 and restoring the CORE config file. Not sure if that would have prevented the issue here, but FYI
I selected the dragonfish update train.
Not sure what was the issue either.
More a small warning to other users, that the upgrade will not always run smooth 
