Why it is difficult to upgrade from 11.04 to 13.04?
1520
How to install software or upgrade from an old unsupported release?
119595
Is it necessary to upgrade to 14.04 LTS or can I stand in 12.04 LTS forever with no problem?
119169
Should I upgrade to 14.04 LTS?
49161
Upgrade manager wants me to do a partial upgrade
30754
Cannot update: "No available releases found"
16578
How to upgrade a single package using apt-get?
6833
Why is my Ubuntu 18.04 distribution asking me to upgrade to Pop!_OS 19.10?
19288
Update manager doesn't offer an upgrade to the new release
59088
How to upgrade to a newer release of Ubuntu using the Live CD?
87906
Why does OS X want me to "upgrade" from El Capitan to Yosemite Beta 4?
7580
How to safely upgrade from an older Ubuntu version to a newer one?
211
Can I skip over releases when upgrading?
115421
Ubuntu 13.10 to 14.04 Lts does not upgrade, keeps showing error
61473
Failed to fetch because of size mismatch error while upgrading
79358
Upgrade High-Trust Addin/App from 2013 to 2016
24165
Upgrade to version newer than repositories
128471
How do I update from 9.0.10 to 9.1.0?