0

I've been running ubuntu 16.04 LTS for some months after upgrading from the previous LTS version. Recently I've run into problems with software updater failing with the message "failed to download repository information". I've read through some similar questions and tried their suggestions, i.e.

sudo apt-get autoclean
sudo apt-get clean
sudo apt-get autoremove

I've also tried different download sources from Software & Updates -> Ubuntu Software panel including the one proposed by "Select Best Server". None of these have worked in fixing the problem.

Here is what I get when I run sudo apt-get update:

$ sudo apt-get update
Get:1 http://mirror.clarkson.edu/ubuntu xenial InRelease [247 kB]
...
Fetched 571 kB in 0s (778 kB/s)
Reading package lists... Done
W: GPG error: ...: At least one invalid signature was encountered.
W: The repository '...' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.

(same message occur with other servers)

Any suggestions on what next to try?

Thanks, Glenn

Kristopher Ives
  • 5,509
gdgilda
  • 1

1 Answers1

0

For some reason your keys are not validating your packages anymore. This can either be because the mirror you are downloading packages from is bad or your keys are bad. Since you already tried changing your mirror it's unlikely your mirror is bad, but instead you are likely missing keys somehow.

Go to the System Settings and open the Software and Updates then go to the Authentication tab. You should see some keys in there like the ones in this screenshot, if not hit the "Reset Defaults" button:

enter image description here

Kristopher Ives
  • 5,509
  • Displaying the above panel shows a list of several keys. Doing a "restore defaults" didn't seem to help. I tried changing servers again and that didn't seem to help either. – gdgilda Dec 17 '16 at 00:37