how to upgrade unsupported release when `apt-get update` fails
1520
How to install software or upgrade from an old unsupported release?
66065
"Unable to connect" error with apt-get?
145400
Error when trying sudo apt-get update - Python related?
4305
How do I fix a "Problem with MergeList" or "status file could not be parsed" error when trying to do an update?
28650
`apt-get update` cannot find Ubuntu servers
122588
Can't connect to ubuntu archive when using apt-get update
21382
What does "sudo apt-get update" do?
64558
What does `do-release-upgrade` really do?
126343
How to downgrade a package via apt-get?
113145
What does 'apt-get install update' do?
11166
"Require Installation Of Untrusted Packages" while upgrading with the update manager
77705
Unable to upgrade in ubuntu
110148
Why does `do-release-upgrade` skip a version?
74990
Error while trying to upgrade from Ubuntu 18.04 to 18.10: "Please install all available updates for your release before upgrading."
76905
Failure [INSTALL_FAILED_ALREADY_EXISTS] when I tried to update my application
35146
Will apt-get dist-upgrade upgrade my system to newer version?
107792
Update information outdated, "Failed to fetch cdrom"