I get the following error message when trying a network upgrade from 10.04 to 10.10:
authentication failed. authenticating the upgrade failed. there may be a problem with the network or with the server
I googled that error and found one proposed solution:
gpg --keyserver keyserver.ubuntu.com --recv 437D05B5
gpg --export --armor 437D05B5 | apt-key add -
However, this seems to have screwed up at least one guy's system.
Is there any safer way of solving this (besides doing a fresh install)?
I did not solve this directly, but found a workaround: I put the latest Ubuntu (11.10) on a USB stick, booted to USB, and selected 'upgrade Ubuntu' from the options. Worked fine.
In my case, I started ubuntu manager from the terminal to find the error. The problem was that /etc/apt/trusted.gpg could not be read.
fixed the problem.