I've tried to upgrade from 16.10 to 17.04 and got the same error. Changed /usr/sbin/do-release-upgrade from
print(_("For upgrade information, please visit:\n" "%(url)s\n") % { 'url' : url }) to print(_("For upgrade information, please visit:\n %(url)s\n") % { 'url' : url }) and upgrade have started. Ubuntu - ignoring bugs over centuries! )) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1499391 Title: do-release-update crashes on lines 126-127 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1499391/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs