Upgrade from 21.04 to 21.10 interrupted and cannot get to recovery mode

When I choose the recovery mode option in grub, I get a blinking screen with the below message:

/lib/recovery-mode/recovery-menu: line 120: /lib/recovery-mode/options/whiptail:: No such file or directory

Any clue?

What I tried so far: Loaded a live usb, chroot to the root partition and run dpkg --reconfigure -a and some apt commands. No luck.

My home directory is in the same partition as root which is a lvm partition. If it is possible to reinstall without affecting /home, I would go with that.

I had this same problem when I attempted to update from Ubuntu 20.04 to 22.04.
I used the steps provided above by Francesco Alagna, however, once I got to the step of running "sudo dpkg --configure -a", I got an error message below:

sudo: symbol lookup error /usr/local/lib/AppProtection/libAppProtection.so: undefined symbol _dl_sym

and I had to do an additional step which I found here: https://ubuntuforums.org/showthread.php?t=2469692&p=14092862#post14092862

You can boot from a "Ubuntu Live cd/usb" and remove de files /usr/local/lib/AppProtection/libAppProtection.so*, and remove or comment line "/usr/local/lib/AppProtection/libAppProtection.so" in the file /etc/ld.so.preload" After that reboot and login again. When you still see errors about /usr/local/lib/AppProtection/libAppProtection.so, just execute ldconfig as root.

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Then after that step I continued the steps provided above by Francesco Alagna. Thank you for saving my system! Matt

I actually had the same problem while upgrading. The comment by @Raffa actually helped a lot. I had to apply some small changes, though.

After running a live distro, I opened a shell and followed these steps:

sudo fdisk -l
sudo mount /dev/(your partition id) /mnt/
sudo mount --bind /proc/ /mnt/proc/
sudo mount --bind /sys/ /mnt/sys/
sudo mount --bind /dev/ /mnt/dev/
sudo cp /etc/resolv.conf /mnt/etc/resolv.conf
sudo chroot /mnt/

Then I continued like this:

sudo mv /etc/ld.so.preload /etc/ld.so.preload.old
sudo dpkg --configure -a
sudo apt update
sudo apt --fix-broken install
sudo apt upgrade

I hope that will help!