Update:
I used a spare HDD on the same laptop and setup 16.04 LTS per Ubuntu Disk Partitioning recommendations as follows: Swap, /, and Home in that order. Grub is on the 1st Primary as boot, Swap, /, and Home are logical on the 1st extended. There are no other operating systems on this HDD. There is only this one HDD physically installed. With this HDD installed as described here I NO LONGER have issues during shutdown or reboot.
If I physically install the original HDD as it is described in this bug description I Still DO have issues with the hang on shutdown and reboot.
I cannot conclude anything but I speculate that the original HDD setup as /, Home, Swap in that order, or the config of fstab may have some significance to the issue.
It has been over 2 months using this new HDD in my laptop without any hangs. There has never been a Target reached Shutdown hang since installing the new HDD. I waited to be sure the hang is gone before reporting any new data. I will keep this new hardware configuration and use the original HDD as a spare for future use.
Thank you for all your efforts to resolve the issue.
Update:
I used a spare HDD on the same laptop and setup 16.04 LTS per Ubuntu Disk Partitioning recommendations as follows: Swap, /, and Home in that order. Grub is on the 1st Primary as boot, Swap, /, and Home are logical on the 1st extended. There are no other operating systems on this HDD. There is only this one HDD physically installed. With this HDD installed as described here I NO LONGER have issues during shutdown or reboot.
If I physically install the original HDD as it is described in this bug description I Still DO have issues with the hang on shutdown and reboot.
I cannot conclude anything but I speculate that the original HDD setup as /, Home, Swap in that order, or the config of fstab may have some significance to the issue.
It has been over 2 months using this new HDD in my laptop without any hangs. There has never been a Target reached Shutdown hang since installing the new HDD. I waited to be sure the hang is gone before reporting any new data. I will keep this new hardware configuration and use the original HDD as a spare for future use.
Thank you for all your efforts to resolve the issue.