LDAP authentication used to work. Testing the connection from the hub GUI settings gives "login Successful" to the LDAP server, but login to IM or UMP fails with non-admin user.
From the HUB log:
Mar 3 12:36:09:285  hub: login [NimBUS] - user does not exist user=a_sas ip=< ip address >
Mar 3 12:37:03:794  hub: login [LDAP] - (logon_user) 0 user found for (&(objectClass=person)(|(userPrincipalNamefirstname.lastname@example.org)(sAMAccountNameemail@example.com)), do not know which to use.
Client had changed the AD password and it contained Norwegian characters (Æ. Ø & Å). He changed it to one without, and then it worked fine.