Here's how I got these two lines (apt-get install samba first):
smbclient -d 255 -U USER -I HOSTNAME '\\'
Server does not support EXTENDED_SECURITY but 'client use spnego = yes and 'client ntlmv2 auth = yes'
I've added these lines into /etc/samba/smb.conf which fixed smbclient, however Kodi still didn't work, I then added them to the user specific config and Kodi succeded connecting to the Airport.
I'm not sure this fixes Windows 10. However the test is simple, just smbclient the IP of your Windows 10 box.