Am I clear enough to explain what the problem is?
Sorry, if I didn't understand. So, Samba is installed, configuration is not working through the Ubuntu tools.
I though I would look an my own Ubuntu system and look at the tools Ubuntu provides. In short, they only tell you part of what you need to know to maintain a system. I could not tell if the two daemons were running; smbd and nmbd. That is critical, if you have a problem.
I opened a command prompt, ran the command 'ps aux | grep smbd' and 'ps aux | grep nmbd'. I found out nmbd was not running. I opened up Webmin, looked at the status screen, and confirmed nmbd was not working. I tried to start it, got a failure. Let me assure you, it was working. It wasn't at this point.
Opened up Synaptic. Search 'samba' and marked the 'installed' in the left column. Some how samba4 was not installed. First of all I had version 3 ( something ) installed. The client is now version 4. So, the constant 'updates' some how did not work, my server code was not there. So, Synaptic, installed Samba4. 5 packages, 110Mb of code later, the server is back... version 4.
Why am I telling you this; simply to show you the "Ubuntu tools" suck.
What I recommend is install from Synaptics, 'swat'. Once installed, open a web browser, and enter;
and press enter. Sign in with the root user, and root password. Now you have a tool that works.
There is a status icon, it will tell you if smbd and nmbd are running. If not, there are restart and stop buttons that run the correct commands to do the work. Simple, you don't have to remember commands.
For your problem, either install swat, or run the command 'ps aux | grep smbd' and 'ps aux | grep nmbd' to know if the daemons are running.
If not, post your /etc/samba/smb.conf file. It contains all your configuration. If you do not have a valid config, one, or both of the daemons may not start.
Let me know... sorry again for not understanding, and for the rant...