Hi,
the toolbar from sql developer data modeler 4.1.3 (also older version) on my macbook pro (15" display, resolution 1680x1050, OS X 10.11.3) is not visible.
Try with Version 4.0x at the start it is for 1 ms visible and then the toolbar go hidden. In lower resolutions get the same problem.
screenshot: 
Do you have an idea?