Get:1 http://security.ubuntu.com/ubuntu xenial-security InRelease [102 kB]
Hit:2 http://cl.archive.ubuntu.com/ubuntu xenial InRelease
Get:3 http://cl.archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB]
Ign:4 http://repo.vivaldi.com/stable/deb stable InRelease
Hit:5 http://repo.vivaldi.com/stable/deb stable Release
Get:7 http://cl.archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB]
Fetched 306 kB in 1s (235 kB/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt-get -f install' to correct these.
The following packages have unmet dependencies:
 linux-image-generic : Depends: linux-image-extra-4.4.0-66-generic but it is not installed
E: Unmet dependencies. Try using -f.