The output you have all mentioned from GPG is not an error - it signifies that GPG has verified the integrity of the downloaded archive (meaning the archive is not corrupt). The Kubuntu-Upgrader wizard will _not_ continue if GPG returns an error (if GPG cannot verify the archive against the signature, in the case that the archive is corrupt).
The output you have all mentioned from GPG is not an error - it signifies that GPG has verified the integrity of the downloaded archive (meaning the archive is not corrupt). The Kubuntu-Upgrader wizard will _not_ continue if GPG returns an error (if GPG cannot verify the archive against the signature, in the case that the archive is corrupt).