Lucid Lynx here..! I can't update my system, neither by Update Manager, nor by command line as root. This is what i got:
Reading package lists... Done
W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used.GPG error: http://deb.opera.com stable Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A2019EA84E7532C8

W: Failed to fetch http://deb.opera.com/opera/dists/stable/Release

W: Some index files failed to download, they have been ignored, or old ones used instead.
demian@demierda:~$

NOW, a pal told me to write this code and i want to check with you guys if it's right:


gpg --keyserver keyserver.ubuntu.com --recv A2019EA84E7532C8
gpg --armor --export A2019EA84E7532C8 --output A2019EA84E7532C8 | sudo apt-key add -

Thanks for reading this..!

It looks like the key you have for the repository at opera.com has expired (or you never had it). The commands that your friend has given you grabs the new key from Ubuntu's keys server and installs it for apt to use. It should work fine.

If for some reason it doesn't resolve your problem then could you post the contents of /etc/apt/sources.list and the exact command you're running prior to the error. But that shouldn't be necessary.

1 members found this post helpful.

The said gpg keys worked fine. next, i used command sudo apt-get update and down came a bunch of updates. The Update Manager loaded automatically, fetched packages and installed them. System updated at last..!!
Thank you guys..!!