I just tested this on a second iMac (Catalania) and on Windows with the free version. On the second Mac I could duplicate the issue. On Windows it is as you wrote, everything is working normally. So that issue concerns only Mac users.
Jim Simon wrote:It makes sense that you can't RiP an Adjustment Clip, as it's dependent for its render on everything beneath it.
Maybe it would be better to remove the RiP option from Adjustemnt Clip altogether then, it's a bit irritating that way. It might not be such a bad idea to have the option available in an Adjustemnt clip as well, then you wouldn't be limited to the clip length and could render a freely selectable range that way.