Update issue

E: The repository 'Index of /gnome3-team/gnome3/ubuntu focal Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'Index of /gnome3-team/gnome3-staging/ubuntu focal Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
This is what I get after sudo apt update. Any ideas?

You have in some point added gnome3-team source to your sourcelist, but it says it's not available for ubuntu 20.04

To remove the list open the app called ' Software & Updates' -> Other Software and untick it.

4 Likes