I use a Lubuntu 16.04 EEE-PC with Kernel 4.4.0-38 which was upgraded from a 14.04 version.
I have in /etc/fstab the line
//192.168.1.99/public /mnt/NAS cifs credentials=/home/hias/.geheim,iocharset=utf8 0 0
which did not give me problems in 14.04, even if the server in question was not running.
In 16.04 the system is not booting using systemd. When I boot with upstart (via GRUB) it works as before. When I outcomment the line in fstab, I can boot with systemd.
So I guess this is a systemd issue.
Any opinions how I can fix it?