Data Modeler 18.104.22.168.899 is out with plenty of important bug fixes. Go and try!
From the download pages:
Oracle SQL Developer Data Modeler 22.214.171.124: Bugs Fixed
Date: December 2015
This list contains only a selection of higher priority bugs, customer bugs and issues raised by the community on the OTN Forum since the release of version 4.1.2.
|22109015||Table structure not available in browser for versioned designs|
|22120662||“Oracle errors to mask” tab is always disabled|
|22112910||Table has columns with undefined security properties’ for xmltype column|
|22186607||Constraint definition is missing in ddl when custom ddl script is used|
|22187312||Error when running design rules using Data Modeler version 126.96.36.1995|