Since upgrading to OES 2018 from 2015 SP1 we are getting this error. We have 3 OES Servers and this started on each one after the upgrade

2018-10-29T15:32:20.076989+00:00 bw-lx-04 namcd[3659]: searchAndFillPwdStruct_fromNDS: Error [-7] in LDAP search while trying to fill passwd structure : filter=uid=(unknown),base=ou=OESSystemObjects,o=Pe ters


Any ideas what this is about?