Grub-customizer fails to save

I think those are carriage returns–I would suppose those would not be in the final version of the file.

The actual error might be caused by the end of the “if” statement, with nothing written for the “then” of it. I’m not sure about that, just it doesn’t look right (it seems like something is supposed to be on that empty line).

This person ran into the same issue, on the same line: Sudo grub-mkconfig -o /boot/grub/grub.cfg does not work They were also using Grub-customizer. It was line 277 in their case, but I checked and it’s the same fi that’s throwing the error.

if [ "$grub_platform" = "efi" ]; then
	fwsetup --is-supported
	if [ "$?" = 0 ]; then

	fi
fi

I think the best thing to do would be to file a bug report as they mentioned in the note you posted.

As for getting Grub straightened out, try removing Grub-customizer for now and see if you can at least get through an update-grub so you have a good config file to boot off of.