404 error while trying to upgrade
1520
How to install software or upgrade from an old unsupported release?
140893
Error when using apt-get update
133
How can I fix a 404 Error when using a PPA or updating my package lists?
76241
"no public key available" while upgrading using update-manager
6173
"method driver /usr/lib/apt/methods/https could not be found" update error
98844
upgrade 14.04 with errors and shows red sign on top
339
How to resolve "Failed to download repository information"?
28650
`apt-get update` cannot find Ubuntu servers
20751
Problem upgrading Ubuntu 9.10
129101
Upgrading Ubuntu 9.04 to 9.10 when Update Manager doesn't let you
421
How do I update a Drupal distribution to a newer version?
59088
How to upgrade to a newer release of Ubuntu using the Live CD?
10633
software updater failed to download repository information
7357
upgrade to 13.10 stalled and restart failed
15687
How do I resume a release upgrade?
86777
Distribution upgrade problem "No new release found"
9901
How to upgrade from 18.10 to 19.10, using the command line?