Last night I had to do some testing under Windows 10 and to my surprise I was unable to access smb network share.
I have done some investigation and it would appear that Windows 10 will try to negotiate SMB3_11, which Samba 4.1.1 doesn’t yet support except in the current 4.3 release candidate.
To fix this I disabled SMB 3 and enabled v1:
To disable SMBv2 and SMBv3 on the SMB client, run the following commands:
sc.exe config lanmanworkstation depend= bowser/mrxsmb10/nsi sc.exe config mrxsmb20 start= disabled
sc.exe config lanmanworkstation depend= bowser/mrxsmb10/mrxsmb20/nsi sc.exe config mrxsmb10 start= auto
After restarting Win10 instance I was back in action.
See more here