This is the offending line that appears at start-up: udev[452]:add_to_rules:unknown key 'RUN{ignore_error}' in /etc/udev/rules.d/z55_hotplug.rules:10
and also: udev[452]:add_to_rules:unknown key 'RUN{ignore_error}' in /etc/udev/rules.d/z55_hotplug.rules:12. After this it looks for the root partition and never finds it to start the system. best wishes, Adam