Fail to sudo apt-get update

Question

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?

Please don't post screenshots of text. Copy the text here and apply code formatting instead. — muru, Nov 16 '16 at 01:58
What shows up when you visit http://security.ubuntu.com/ubuntu in a browser? Is it the "Index of /ubuntu" page or something else? — Chai T. Rex, Nov 16 '16 at 02:13
I was not able to post text in here with more than 2 hyperlinks. — Mel Huang, Nov 18 '16 at 00:39
David, the link you posted in here was 50% solution of my answer. Thanks. — Mel Huang, Nov 18 '16 at 00:53
I just rolled back your last edit. Please don't add the answer to your question and please don't duplicate the answers of the linked question. Thanks. — David Foerster, Nov 18 '16 at 02:12

score 2 · Accepted Answer · answered Nov 16 '16 at 11:15

2

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

answered Nov 16 '16 at 11:15

GAD3R

1

It worked for fixing the missing keys. Thanks. – Mel Huang Nov 18 '16 at 00:52

1 Answers1