Could not download all repository indexes
The repository may no longer be available or could not be contacted because of network problems. If available an older version of the failed index will be used. Otherwise the repository will be ignored. Check your network connection and ensure the repository address in the preferences is correct.
Followed by:
The repository '
https://brave-browser-apt-release.s3.brave.com stable Release' does not have a Release file.Updating from such a repository can't be done securely, and is therefore disabled by default.See apt-secure(8) manpage for repository creation and user configuration details.
The repository '
http://apt.connectify.me speedify Release' does not have a Release file.Updating from such a repository can't be done securely, and is therefore disabled by default.See apt-secure(8) manpage for repository creation and user configuration details.
The repository '
http://dl.google.com/linux/earth/deb stable Release' does not have a Release file.Updating from such a repository can't be done securely, and is therefore disabled by default.See apt-secure(8) manpage for repository creation and user configuration details.
The repository '
https://mirrors.cicku.me/linuxmint/packages una Release' does not have a Release file.Updating from such a repository can't be done securely, and is therefore disabled by default.See apt-secure(8) manpage for repository creation and user configuration details.
The repository '
http://security.ubuntu.com/ubuntu focal-security Release' does not have a Release file.Updating from such a repository can't be done securely, and is therefore disabled by default.See apt-secure(8) manpage for repository creation and user configuration details.
The repository '
http://ppa.launchpad.net/sicklylife/gnucash/ubuntu focal Release' does not have a Release file.Updating from such a repository can't be done securely, and is therefore disabled by default.See apt-secure(8) manpage for repository creation and user configuration details.
The repository '
http://ppa.launchpad.net/webupd8team/y-ppa-manager/ubuntu focal Release' does not have a Release file.Updating from such a repository can't be done securely, and is therefore disabled by default.See apt-secure(8) manpage for repository creation and user configuration details.
The repository '
http://ddebs.ubuntu.com focal Release' does not have a Release file.Updating from such a repository can't be done securely, and is therefore disabled by default.See apt-secure(8) manpage for repository creation and user configuration details.
The repository '
http://ddebs.ubuntu.com focal-updates Release' does not have a Release file.Updating from such a repository can't be done securely, and is therefore disabled by default.See apt-secure(8) manpage for repository creation and user configuration details.
The repository '
https://dal.mirrors.clouvider.net/ubuntu focal Release' does not have a Release file.Updating from such a repository can't be done securely, and is therefore disabled by default.See apt-secure(8) manpage for repository creation and user configuration details.
The repository '
https://dal.mirrors.clouvider.net/ubuntu focal-updates Release' does not have a Release file.Updating from such a repository can't be done securely, and is therefore disabled by default.See apt-secure(8) manpage for repository creation and user configuration details.
The repository '
https://dal.mirrors.clouvider.net/ubuntu focal-backports Release' does not have a Release file.Updating from such a repository can't be done securely, and is therefore disabled by default.See apt-secure(8) manpage for repository creation and user configuration details.
The repository '
http://archive.canonical.com/ubuntu focal Release' does not have a Release file.