Without knowing more about your smb setup, as the above poster asked, try this:
swipe right on the smb tab, choose the pencil icon for settings, change: smb1=true and try that. Also in that dialog page, enter the user name and password there also, if your setup requires it, if not, leave it blank.
you can also choose the search local button and maybe find the correct connection info. I find that hit or miss on my Linux Mint Mate persistent setup, though. On the scan window I often have to hit refresh several time to get the info. On my device it will initially show smb://192.168.2.255, instead of the true, smb://192.168.2.2. Maybe someone with more networking knowledge will clarify.
In my case I am connecting to a wireless, home router.