I struggled with the same issue on a fresh Kubuntu 20.04 installation (Lenovo Thinkpad P52s).
>From the Grub / Advanced options / Recovery mode / root terminal I was able to remount the / as rw (rather than ro) Changing 'lz4' to 'gzip' as per https://forums.linuxmint.com/viewtopic.php?f=46&t=323152 and running update-initramfs -c -k $(uname -r) I had a new issue: the fstab entry UUID=3e757667-25352354... was not resolved. To solve this I had to: manually changed the fstab entry from UUID=... to /dev/nvme0n1p2 change COMPRESS=lz4 to gzim in /etc/initramfs-tools/initramfs.conf update-initramfs as per above reboot -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1835660 Title: initramfs unpacking failed To manage notifications about this bug go to: https://bugs.launchpad.net/oem-priority/+bug/1835660/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs