apt-get update: "GPG error: Clearsigned file isn't valid, got 'NODATA'"
24355
Got NODATA issue: 'NODATA' (does the network require authentication?)
95593
sudo apt-get update returns an error
6105
What is the easiest way to resolve apt-get BADSIG GPG errors?
56150
Can't upgrade/update ubuntu 18.04 as apt/dpkg error is showing up
24603
apt-get upgrade gives "403 forbidden" error
75879
How do I get add-apt-repository to work through a proxy?
137317
libdvd-pkg: `apt-get check` failed, you may have broken packages. Aborting
119943
Where can I find a repository for older unsupported releases?
48418
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures couldn't be verified because the public key is not available:
9896
How do I get and modify the source code of packages installed through apt-get?
93574
E: Some index files failed to download. They have been ignored, or old ones used instead after apt-get update
96391
dpkg exit with error parsing file `/var/lib/dpkg/status`, what to do?
96143
How to resolve "dpkg: error processing /var/cache/apt/archives/python-apport_2.0.1-0ubuntu9_all.deb"?
83216
apt get update missing release file
49149
How do I solve "Unable to fetch some archives, maybe run apt-get update or try with --fix-missing" error?
74227
dpkg error when using apt-get install
122588
Can't connect to ubuntu archive when using apt-get update