[xekon]

I had this issue, the client Kodi 18 beta3 on Ubuntu machine

it would not just let me use the IP Address for the server name

xml:
192.168.1.150

instead I had to add the backslashes

xml:
\\192.168.1.150

So I browsed to Videos / Files

Next click Add videos / Browse / Add network location

server name: \\192.168.1.150
shared folder: vid1
username: smb-username
password: smb-password