Unable to upgrade
3298
How do I resolve unmet dependencies after adding a PPA?
30754
Cannot update: "No available releases found"
116445
"Can't check signature: public key not found" while upgrading, why?
20751
Problem upgrading Ubuntu 9.10
13970
Why am I not getting the Ubuntu 18.04 upgrade?
67481
How to revert a do-release-upgrade?
146675
Error 101: Network is unreachable when trying to update
76241
"no public key available" while upgrading using update-manager
93942
How to fix "Failed to download repository information" error while updating?
41519
What can I do if a package is not available on the newest version of Ubuntu (18.04) but is available on older versions?
36696
Unmet dependencies unable to fix
24165
Upgrade to version newer than repositories
65099
Unable to install any updates through update manager/apt-get upgrade
129143
Error upgrading to High Sierra
94171
Why Does Software Updater Say No updates Available, but apt-get upgrade Shows updates available?
61473
Failed to fetch because of size mismatch error while upgrading
107993
Unable to upgrade Windows 10 edition from Home to Pro