How to get rid of this post "requires installation of untrusted packages"?
6809
How do I fix the GPG error "NO_PUBKEY"?
12054
How do I deal with "unauthenticated sources" errors in the Software Center?
60659
Install newer package version from trusty-backports
16736
"The following packages have been kept back:" Why and how do I solve it?
32220
How to resolve Unmet dependencies error?
36696
Unmet dependencies unable to fix
102559
How to install package from newer distribution?
33175
Installing suggested/recommended packages?
117852
"Package dependencies cannot be resolved" error when installing software
44991
A lot of missing dependencies when I try to install all software
154848
How can I install 'restricted-extras' offline?
112267
Can you help me with my software dependency issue?
121222
"Kept back" packages for update , want to uninstall unity?
5830
How to prevent updating of a specific package?
53588
How do remove the CD / DVD install as a source for apt-get packages when installing new features?
73068
cant install or remove anything on 18.04 cause of DPKG error
45526
How can I install packages without starting their associated services?