Right, if the boot repair guide didn't work (you haven't posted to say that the problem has been resolved), I would suggest chrooting into your install from a live USB and then reinstalling GRUB. This is the guide I have used a few times in the past (admittedly for BIOS not UEFI systems) when I have broken my GRUB install: https://wiki.manjaro.org/index.php?title=Restore_the_GRUB_Bootloader
Bare in mind that the guide there is for Manjaro, so not all of it will be completely applicable (i.e. package manager commands).
.png "Funny")
Ian Goppert got a reaction from HotCheeseNachozAndBurritoz in Is there even a good OS in this universe?
Ian Goppert reacted to Koeshi in Having a ruff time with GRUB bootloader.png "Funny"){kind=small}
