I had a 21.04 system that gave no warnings when I ran apt update, but then I ran this command (suggested by the internet)
add-apt-repository universe
and after that I get warnings when running
apt update
The warnings are
W: Skipping acquire of configured file 'universe/binary-amd64/Packages' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'universe' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'universe/binary-i386/Packages' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'universe' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'universe/i18n/Translation-sv' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'universe' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'universe/i18n/Translation-sv_SE' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'universe' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'universe/i18n/Translation-en' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'universe' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'universe/dep11/Components-amd64.yml' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'universe' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'universe/dep11/icons-48x48.tar' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'universe' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'universe/dep11/icons-64x64.tar' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'universe' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'universe/dep11/[email protected]' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'universe' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'universe/cnf/Commands-amd64' as repository 'http://archive.canonical.com/ubuntu hirsute InRelease' doesn't have the component 'universe' (component misspelt in sources.list?)
Here is the content of my /etc/apt/sources.list
# deb cdrom:[Ubuntu 20.04 LTS _Focal Fossa_ - Release amd64 (20200423)]/ focal main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://se.archive.ubuntu.com/ubuntu/ hirsute main restricted
# deb-src http://se.archive.ubuntu.com/ubuntu/ focal main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://se.archive.ubuntu.com/ubuntu/ hirsute-updates main restricted
# deb-src http://se.archive.ubuntu.com/ubuntu/ focal-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://se.archive.ubuntu.com/ubuntu/ hirsute universe
# deb-src http://se.archive.ubuntu.com/ubuntu/ focal universe
deb http://se.archive.ubuntu.com/ubuntu/ hirsute-updates universe
# deb-src http://se.archive.ubuntu.com/ubuntu/ focal-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://se.archive.ubuntu.com/ubuntu/ hirsute multiverse
# deb-src http://se.archive.ubuntu.com/ubuntu/ focal multiverse
deb http://se.archive.ubuntu.com/ubuntu/ hirsute-updates multiverse
# deb-src http://se.archive.ubuntu.com/ubuntu/ focal-updates multiverse
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://se.archive.ubuntu.com/ubuntu/ hirsute-backports main restricted universe multiverse
# deb-src http://se.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu hirsute partner universe
# deb-src http://archive.canonical.com/ubuntu focal partner
deb http://security.ubuntu.com/ubuntu hirsute-security main restricted
# deb-src http://security.ubuntu.com/ubuntu focal-security main restricted
deb http://security.ubuntu.com/ubuntu hirsute-security universe
# deb-src http://security.ubuntu.com/ubuntu focal-security universe
deb http://security.ubuntu.com/ubuntu hirsute-security multiverse
# deb-src http://security.ubuntu.com/ubuntu focal-security multiverse
# This system was installed using small removable media
# (e.g. netinst, live or single CD). The matching "deb cdrom"
# entries were disabled at the end of the installation process.
# For information about how to configure apt package sources,
# see the sources.list(5) manual.
EDIT: Added /etc/apt/sources.list and tried to clarify what I did to mess up my system.
