Comment 1 for bug 196075

Thank you for taking the time to report this issue and help to improve Ubuntu.

It is impossible to ever guarantee with 100% certainty that the bootloader will succeed until the attempt is made; this is a limitation inherent to software. Any failures to correctly boot are certainly bugs, and all such bugs are taken seriously, but they can't all be solved and eliminated before they're seen.

At any rate, if the files are missing from /boot, this sounds to me like a bug in grub-installer rather than in grub; reassigning to that installer component.