My fstab for connecting to a local NAS was always
//192.168.111.112/RAID /home/moi/share/OMV cifs noauto,users,username=USERNAME,passwd=PASSWORD
After upgrading my system from Lubuntu 16.04 to 18.04 this did not work any more, giving the error-message:
Failed to query password: Permission denied
Password for USER@//192.168.111.112/RAID: mount error(22): Invalid argument
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)