Well that error pretty much sums it up, the root account is locked.
Try this: Qubes won’t start - not enough disk space - #2 by BEBF738VD
Instead of mounting a vm, mount the root lv:
mount /dev/qubes_dom0/root /mnt
chroot into it if necessary. That should get you going.
Thank you I unlocked root and logged but I’m still stuck in emergency mode and I can’t start xfce
