[Samba] Lanman passwords NOT PERMITTED for user

[Mark Foley]

I'm using Samba 4.1.23 on Linux Slackware64 14.1.  This host is an AD/DC for a domain having
mostly Windows workstations.  Everything has been working fine for well over a year. 

However, It's been about 8 months since I've added a new user and I did so today using RSAT on
one of the Windows workstations. But, this user cannot log on. The Samba log gives the message:

Lanman passwords NOT PERMITTED for user

No idea what this means "lanman auth" is not configured in smb.conf, but has never been and all
users can log on without problem.

Can someone tell me what the problem is? 

THX --Mark