With new releases of Enterprise Architect there could be changes to the underlying project structure, such as more tables or changed queries. If you are using replicas to share and work with Enterprise Architect projects, it is very important that you open the Design Master before opening any of the replicas with an updated version of Enterprise Architect.
Warning: Upgrading Replicas takes special care!
Changes to the database design in a replica set can ONLY be done to the Design Master. Next time the replicas are synchronized with the Master, the design changes are propagated through to the replicas. Trying to update a replica first at best does nothing, and at worst causes the update of the Master to fail.
One other strategy is to remove replication from a copy of the replica set, upgrade that project and convert it into a new Design Master from which new replicas are created.