[Samba] Solve Err 53 through Samba?

[Gilles]

Hello

Is there a simple way on Samba to solve Err 53 when connecting from 
Windows10 to a guest-enabled server, so I don't have to tweak Windows 
clients?

===================
[global]
         bind interfaces only = Yes
         interfaces = 192.168.0.15/255.255.255.0 127.0.0.1/255.255.255.255
         domain master = Yes
         os level = 255
         preferred master = Yes
         load printers = No
         printcap name = /dev/null
         guest account = www-data
         map to guest = Bad User
         security = USER
         wins support = Yes
         idmap config * : backend = tdb
         printing = bsd
         hosts allow = 127.0.0.1 192.168.0.0/24
         hosts deny = 0.0.0.0/0

[sdcard]
         path = /mnt/sdcard
         create mask = 0775
         guest ok = Yes
         read only = No
===================

Thank you.