Can't drag elements on to the Elemental Display Rack

I purchased the Elemental Display Rack in my scenario family, after having a Sim follow the Collector aspiration, but I haven't been able to add any of the elements sent back from the Geo Council to the Display. I made sure they were in the correct form to add, but none of them can be added to it. I've attached a screenshot of what happens when I attempt to drag an element on to the rack.

I've tried resetting the game with no luck. Any ideas?