In the midst of removing a package that frequently crashes* and
attempting a general package update/upgrade, somehow the package
upgrade system has borked something.

Specifically it seems to have come about following a
sudo apt autoremove where a depreciated image was listed to go.

Now I am at a state where I can do nothing package wise

..........Error Message........
Removing linux-image-4.9.0-6-amd64 (4.9.88-1+deb9u1) ...
/etc/kernel/postrm.d/initramfs-tools:
update-initramfs: Deleting /boot/initrd.img-4.9.0-6-amd64
/etc/kernel/postrm.d/zz-update-grub:
/usr/sbin/grub-mkconfig: 32: /etc/default/grub:
Syntax error: EOF in backquote substitution
run-parts: /etc/kernel/postrm.d/zz-update-grub exited with return code
2 dpkg: error processing package linux-image-4.9.0-6-amd64 (--remove):

..........................................
Either it is a script error in /usr/sbin/grub-mkconfig
or some data file has become corrupted.

Can someone tell me of a fix?
Or other tasks to fix this?

*I suspect the crashes are related to a hardware problem in either
Incompatible RAMM sticks or yet another "Memeory problem" pertainng to
AMD B350 Hardware.