Microsoft changed the dialect for Windows 10 from 0x0310 to 0x0311 see frames 45 (with current smbclient in master trying dialect 0x0310) and Windows falling back to 0x0302 in frame 48 in the response (see attached trace).
Created attachment 10763 [details] wireshark trace of smbclient from samba master failing to get most current dialect connecting to Windows 10 server
Created attachment 10764 [details] wireshark trace of modified smbclient (using 0311 instead of 0310 dialect) works
Created attachment 10765 [details] patch against master to fix incorrect dialect
Created attachment 10864 [details] updated patch to fix obsolete dialect Found additional places where a string of the form *3_10* was used to refer to the dialect so changed these to avoid confusion (to 3_11 to match the new dialect)