I removed a check constraint from a table in my model. Then wanted to Synchronize data dictionary. The Compare models-dialog sees the difference but as I check the To drop-box (which is unchecked by default) and click DDL Preview the Preview is empty. I mean it’s totally empty, not even the standard ddl-comments like
-- Generated by Oracle SQL Developer Data Modeler 184.108.40.2066
show up! Therefore I assume this behaviour to be a bug.