ERROR MESSAGE: untrusted packages and libdrm-nouveau1a libdrm-radeon1
12054
How do I deal with "unauthenticated sources" errors in the Software Center?
153266
errors upgrading from 14.04 to 16.04 about Unknown Multi-Arch type for compiz, libkf5akonadisearch-bin packages
110710
Bad quality of package for installing Linux kernel
133
How can I fix a 404 Error when using a PPA or updating my package lists?
56467
/usr/ucb/cc: language optional software package not installed
36696
Unmet dependencies unable to fix
93827
Unable to locate package libsystemd-dev
117852
"Package dependencies cannot be resolved" error when installing software
11166
"Require Installation Of Untrusted Packages" while upgrading with the update manager
122135
Attempting to compile kernel yields a certification error
4853
Trouble downloading packages list due to a "Hash sum mismatch" error
30571
E: Package 'libpng12-0' has no installation candidate [ubuntu 16.10 Gnome]
31793
The following packages have unmet dependencies!
6851
How do I install the ubuntu-restricted-extras package?
155918
What information do I need to solve an APT dependency issue?
3584
I encountered a gconf2 error while installing some packages, what should I do?
118543
How can I install a package without installing some dependencies?