'update-manager' E:can not open /var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_focal-backports_InRelease - fopen (13: Permission denied), E:The package lists or status file could not be parsed or opened.

[Mr.Duly]

Ubuntu 20.04.2 LTS
08jun21
System
Could not initialize the package information
An unresolvable problem occurred while initializing the package information.
Please report this bug against the 'update-manager' package and include the following error message: E:can not open /var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_focal-backports_InRelease - fopen (13: Permission denied), E:The package lists or status file could not be parsed or opened.

This error actually does not let the system Update properly . Looking for some help on the matter. Like How did this happen? How to fix the issue at hand as well as how to keep this from happeing again.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Roman Grinyov (w3lifer)]

I don't know if this is related or not, but I have a similar error and when I click the corresponding icon in the notification area and then "Show updates" (see attachment), then the file [/var/crash/_usr_bin_update-manager.1000.crash] is updated: https://pastebin.ubuntu.com/p/5MSWkVzfp3