do-release-upgrade fails on 12.04LTS to 14.04LTS server error: An unresolvable problem occurred while calculating the upgrade
5820
How to fix the “Unable to calculate upgrade” issue from command line when upgrading from 12.04 to 14.04?
121201
Why can't I update applications without upgrading the whole OS?
30754
Cannot update: "No available releases found"
11166
"Require Installation Of Untrusted Packages" while upgrading with the update manager
144172
How to upgrade to a point release from the same base release (12.04 to 12.04.03)
15687
How do I resume a release upgrade?
48809
"The upgrade has aborted" error, how to proceed?
120229
Understanding various update and upgrade commands
115421
Ubuntu 13.10 to 14.04 Lts does not upgrade, keeps showing error
91491
How can I get "delta" packages to optimize apt-get upgrade downloads?
109677
How do I to resolve unmet dependencies to uninstall and reinstall package
97346
Is it possible to skip releases during an upgrade?
61473
Failed to fetch because of size mismatch error while upgrading
129101
Upgrading Ubuntu 9.04 to 9.10 when Update Manager doesn't let you
74990
Error while trying to upgrade from Ubuntu 18.04 to 18.10: "Please install all available updates for your release before upgrading."
8525
Error Updating: izx/askubuntu/ubuntu xenial Release' does not have a Release file
58573
Broken package after update: linux-headers, error: BrokenCount >0