I can't start the upgrade form 13.10 to 14.04
19288
Update manager doesn't offer an upgrade to the new release
111573
What's the best way to re-enable PPAs/repos after an upgrade?
118978
Not all updates can be installed: partial upgrade
29191
Upgrade to 18.04 from 17.10
1520
How to install software or upgrade from an old unsupported release?
77692
How do I update Drush to the latest available version?
101714
Is there any way to roll back the most recent upgrade?
115421
Ubuntu 13.10 to 14.04 Lts does not upgrade, keeps showing error
113056
How to upgrade from 12.04 to 12.10 using CD?
98844
upgrade 14.04 with errors and shows red sign on top
144507
No facility exists in Update Manager to upgrade to a new version, why?
89856
How to resume the interrupted upgrade from 14.10 to 15.04?
135383
Unable to update my system Ubuntu13.04: Getting message - requires installation of untrusted packages
67481
How to revert a do-release-upgrade?
5316
Update from 14.04 to 16.04 failed with GPG error
76248
"Failed to start session" after interrupted upgrade to 14.04
64744
Restarted computer during update; "the system network service is not compatible with this version"