If you are migrating a multi-master replicated topology, a situation will arise where a 6.0 master is replicating to a version 5 server. In this situation, an object class violation will occur if changes are made to the new password policy attributes on the 6.0 server, and replicated to the version 5 server. The password policy attributes are managed internally by the server but they might be updated in the event of a bind, a user password modify, or the addition of an entry with the userpassword attribute.
To avoid the object class violation, the 6.0 password policy schema file (00ds6pwp.ldif) must be copied to every version 5 server that will be supplied by a 6.0 master. When the password policy schema file has been copied, restart the version 5 server.