Package gnome tweak tool is not available. package 'gnome-tweak-tool' has no installation candidate
3523
What does "Package  has no installation candidate" mean?
154526
How to upgrade to GNOME 3.30 on Ubuntu 18.04.1
43579
I cannot install new packages: "Could not get lock /var/lib/dpkg/lock"
73196
What can I use instead of gnome-open?
136861
How to install unity desktop over gnome?
132036
Will GNOME 3.38 ever be in the official Ubuntu 20.04 repositories?
28805
dpkg warning files list file for package missing
19035
Will GNOME be updated to 3.30 in Ubuntu 18.04 by itself?
76803
gnome-shell-extensions-user-theme won't install due to unmet dependencies
156977
Unable to install files with apt-get: "unable to locate package"
30588
Unable to locate package
77176
Missing settings in GNOME control center installed in Ubuntu MATE
23582
How to revert to GNOME Classic Desktop?
62476
E: Package '' has no installation candidate
118754
Package dependencies cannot be resolved
91571
How do I install, update and remove GNOME Shell Extensions?
85724
Cannot update/get any packages. gedit not installed