Can you please attach your /etc/apt/sources.list and /var/log/update- manager files using the "attach files" in upper left side of this screen. Thank you for reporting this bug.
-- Main windows fails with "SystemError" if malformed line in sources.list https://launchpad.net/bugs/63019 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
