I have been running 20.04 on an RPi4 with MATE desktop.
I usually run update and upgrade about once per week.
Today I got many error messages, the first one being:
Setting up linux-image-5.4.0-1013-raspi (5.4.0-1013.13) ...
Failed to create symlink to vmlinuz-5.4.0-1013-raspi: Operation not permitted at /usr/bin/linux-update-symlinks line 64.
dpkg: error processing package linux-image-5.4.0-1013-raspi (--configure):
installed linux-image-5.4.0-1013-raspi package post-installation script subprocess returned error exit status 1
Following the errors, uname -a gives me:
Linux ubuntu 5.4.0-1012-raspi #12-Ubuntu SMP Wed May 27 04:08:35 UTC 2020 aarch64 aarch64 aarch64 GNU/Linux
Any suggestions?