after upgrade everything seems fine , except when i want to update/upgrade/install packages , dpkg fails to remove old unused kernels.
after running sudo apt upgrade
the following error happens:
The following packages will be REMOVED:
linux-image-4.4.0-210-generic
The following packages have been kept back:
gimp-gmic php-curl
0 upgraded, 0 newly installed, 1 to remove and 2 not upgraded.
9 not fully installed or removed.
Need to get 0 B/8,021 kB of archives.
After this operation, 7,255 kB disk space will be freed.
Do you want to continue? [Y/n] y
(Reading database ... 599373 files and directories currently installed.)
Removing linux-image-4.4.0-210-generic (4.4.0-210.242) ...
/etc/kernel/postrm.d/initramfs-tools:
update-initramfs: Deleting /boot/initrd.img-4.4.0-210-generic
/etc/kernel/postrm.d/zz-update-grub:
Sourcing file `/etc/default/grub'
/usr/sbin/grub-mkconfig: 11: /etc/default/grub: 2012: not found
run-parts: /etc/kernel/postrm.d/zz-update-grub exited with return code 127
dpkg: error processing package linux-image-4.4.0-210-generic (--remove):
installed linux-image-4.4.0-210-generic package post-removal script subprocess returned error exit status 1
Errors were encountered while processing:
linux-image-4.4.0-210-generic
E: Sub-process /usr/bin/dpkg returned an error code (1)
EDIT 1:
after using @N0rbert solution , i think kernel is upgraded correctly , and now CLI upgrade just crashes and show's no error , and update-manager show's the following error , should i force install?
EDIT 2 : thanks to @guiverc comment, because of extensive changes in 18.04 and above , a fresh install is suggested by Lubuntu team . i will install 20.04 .