Comment 1 for bug 1170183

Thanks for reporting this issue, Dan. Can you confirm that the install on the hard drive that fails to boot was installed under secure boot mode? When the system fails to boot, what exactly do you see on the screen - where does it stop? (Screenshots would be good here)

After booting the system in non-secureboot mode, can you please run the command 'sudo efibootmgr -v' and post the output?