I've recently purchased NUC7PJYH, which has the same issue (bios 0045, ubuntu 18.04 & 16.04). The system was unstable and freezed ocassionally, mostly during startup.
Since the mce error suggests a problem with the microcode update, which probably fixes infamous processor bugs, I've disabled Spectre and Meltdown mitigations in kernel by setting the following parameters in /etc/default/grub:
GRUB_CMDLINE_LINUX_DEFAULT="nopti nospec nospectre_v2"
then running update-grub and restarting.
No startup problems since then. Can you try it?