I've just found the source of this error; somehow, grub-customizer changed /etc/default/grub with a bogus last line:
GRUB_FONT="/boot/grub/unicode.pf2"GRUB_GFXPAYLOAD_LINUX=None
instead of: GRUB_FONT="/boot/grub/unicode.pf2"
I've just found the source of this error; somehow, grub-customizer changed /etc/default/grub with a bogus last line:
GRUB_FONT= "/boot/ grub/unicode. pf2"GRUB_ GFXPAYLOAD_ LINUX=None
instead of: "/boot/ grub/unicode. pf2"
GRUB_FONT=