Updates – Fix ‘sudo apt-get update’ Failure


I am not able to sudo apt-get update successfully. I am using Ubuntu 16.04.1 LTS

Error message:

W: GPG error: http://security.ubuntu.com/ubuntu xenial-security InRelease: At least one invalid signature was encountered.

More error messages attached in the screenshot.

There are lots of "not signed" and "can't be authenticated" error messages.

How could I fix it?

Best Answer

You should use the --allow-unauthenticated option to skip it:

sudo apt-get --allow-unauthenticated update
sudo apt-get --allow-unauthenticated upgrade

Or if you have have the id of the missing key (from the output of apt-get), you can add it to the apt key manager to be authenticate :

 sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys put_the missing_key_here
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