Here is what I see in my terminal:
user@user-OptiPlex-9020:~$ sudo apt-get update
Ign http://extras.ubuntu.com trusty InRelease
Ign http://in.archive.ubuntu.com trusty InRelease
Get:1 http://dl.google.com stable InRelease
100% [1 InRelease gpgv 1,661 B] [Connecting to 192.168.0.90 (192.168.0.90)] [WaSplitting up /var/lib/apt/lists/partial/dl.google.com_linux_chrome_deb_dists_stable_InRelease intoIgn http://dl.google.com stable InRelease
E: GPG error: http://dl.google.com stable InRelease: Clearsigned file isn't valid, got 'NODATA' (does the network require authentication?)
I have the required authentication information in /etc/apt/apt.conf file:
Acquire::http::proxy "http://username:[email protected]:8080/";
Acquire::https::proxy "https://username:[email protected]:8080/";
Acquire::ftp::proxy "ftp://username:[email protected]:8080/";
I am not able to figure out the problem.
One way for that is to remove dl.google.com from your software update repositories,
for that, use System Settings -> Software & Update -> Other Software
and uncheck dl.google.com
then run
sudo apt-get update
I could not find a way to keep google in circle because I live in Iran & google refuses service to users in Iran.