I have been running OMV 2.0 (latest) on my ODroid XU4 for about 6-8 months now with great success, and absolutely no issues with SMB/CIFS shares. Today, I decided to go ahead and upgrade to 3.0, and after learning the hard way that upgrading in place is a bad idea, have my server mostly back up and running (clean install of Jessie with OMV 3.0 installed on top). Unfortunately though, for some reason I cannot enable the SMB/CIFS service. When doing so through the Web GUI, I toggle the "Enable" switch, click Save, and after sitting there for a minute or two on the "Saving..." spinner, I just get a generic error that says "communication failure" with "OK" and "Show Details" buttons, neither of which do anything when clicked. After that I just have to reload the Web GUI or close the window.
I've searched every way I can think of, and can't find someone reporting a similar issue, so I may be unique (or, more likely, someone will immediately be able to link me to a solution :)). If anyone has any ideas, they would be greatly appreciated.