Disclaimer: This is dangerous as it might cause a corrupt file system. This KB should be used with Axcient's Tech Support guidance.
Force the system off so grub appears after a dirty shutdown
Hit E on the top line
Scroll down to the line that starts with "linux /boot" and go to the end of it and add "init=/bin/bash" without the quotes
Hit F10 to boot
When you arrive at the command prompt type"
mount -o remount,rw /
Enter your new root password twice
mount -o remount,ro /
At this point you can try 'reboot' or 'shutdown -r now' but if those fail the power button is the only option. After the system comes back log in as root and:
initctl start asyncreboot
The system will reboot again and after that everything should start fine.