So we were moving a NIS database to LDAP under SUSE SLES 10 using the MigrationTools-47 scripts. It generated the ldif file, but would not import because it was failing on adding groups. This was the error we were getting:
(65) no structural object class provided
All we had to do is change this:
objectClass: posixGroup
objectClass: top
to this:
objectClass: posixGroup
objectClass: namedObject
objectClass: top
for each group in the ldif file. Then we redid slapadd -l file.ldif and everything worked.