On MAC mini (Late 2012), OS X EI Capitan Version 10.11.5
All R.U.B.E Versions After 1.6.1 have the same problem:
When you select an item from the item list, the item properties do not display, if you want to display them, you must select the item from the main scene, just as the image shows below:
item properties do not display
Re: item properties do not display
Thanks for the report - I can reproduce this on Linux too.