your error is in this file it seems:
/etc/default/grub: 30: Syntax error: EOF in backquote substitution
can you paste the contents of /etc/default/grub ? seems some tool you used or some manual edit broke its contents.
your error is in this file it seems:
/etc/default/grub: 30: Syntax error: EOF in backquote substitution
can you paste the contents of /etc/default/grub ? seems some tool you used or some manual edit broke its contents.