I noticed the following in system logs and on the server console. The server is a PDC server in classic domain , DomainA. Samba 4.4.5. Trusts are setup with Domain A and C. #:/var/adm# tail -100 messages Dec 23 08:46:25 xxx nmbd[1784]: [ID 702911 daemon.error] [2016/12/23 08:46:25.095399, 0] ../source3/nmbd/nmbd_workgroupdb.c:56(name_to_unstring) Dec 23 08:46:25 xxx nmbd[1784]: [ID 702911 daemon.error] name_to_nstring: workgroup name DOMB ^[ is too long. Truncating to Dec 23 08:46:25 xxx nmbd[1784]: [ID 702911 daemon.error] [2016/12/23 08:46:25.155424, 0] ../source3/nmbd/nmbd_workgroupdb.c:56(name_to_unstring) Dec 23 08:46:25 xxx nmbd[1784]: [ID 702911 daemon.error] name_to_nstring: workgroup name DOMCCCCCCCCCCC ^[ is too long. Truncating to Dec 23 08:47:03 xxx smbd[4560]: [ID 702911 daemon.error] [2016/12/23 08:47:03.903846, 0] ../lib/param/loadparm.c:772(lpcfg_map_parameter) Dec 23 08:47:03 xxxx smbd[4560]: [ID 702911 daemon.error] Unknown parameter encountered: "display charset" DomainB has a 4 character name. DomainC has 14 characters. Something seems to be padding the names out to just over 15 characters. I have seen other posts on this subject but there did not seem to be a clear answer. On the member servers, wbinfo -i and getent passwd can't allocate UID numbers to trusted users. (The PDC and BDC are ok.) Thanks