I did not follow through the migration path you list in the second edit, but your "out-of-date" comment in the first edit many well be the problem. So, two points:
1. When that 2009 SDDM white paper was published, the Data Modeler was not integrated into SQL Developer, it was standalone.
2. There is a dedicated forum for Data Modeler discussions: SQL Developer Data Modeler
Therefore, my recommendation would be either to:
1. Ask this question in the other forum.
2. Try an older, standalone version of Data Modeler. Trace back through the previous releases starting here: SQL Developer Data Modeler Downloads</title><meta name="Title" content="SQL Developer Data Model…