Comment 37 for bug 1309617

I never experienced any significant problems because of this bug. It only results in those error messages. If your system fails to boot or other things crash, that is probably due to a different unrelated issue.

The "sleep" in /etc/init/plymouth-upstart-bridge.conf does make these error messages go away, but it gives an "Unknown stanza" error instead, so it's not really a solution. I'm not even sure if plymouth-upstart-bridge runs when there is an unknown stanza there, so it could make things worse.

This problem is not present in recent Ubuntu versions when using systemd instead of upstart.