a few questions which should isolate this:
1. Is samba installed at the memberserver?
2. Did you use the memberserver as share host in the share definition in the UMC?
3. Is the share visible with smbclient at the memberserver?
smbclient -U Administrator -L \\localhost
4. Are you using Samba4 as Active Directory controller at your DC Master?
5. Is the windows client succesfully joined to the domain/member of the workgroup?