I am running into a similar Issue. I had not opened RIR for a week or so and ran the new updated installer last night around around 8 PM PMT since I was running into the very issue posted on the forum last yesterday. See link here:
The above thread fixed the issue of getting RIR to open within Revit. However, after running the installer last night I now running into the same issue as @Matthew_Breau when trying to use any sort of picker. This is what I am getting from RIR/GH
I have tried to use the other options of dropdown, checkbox, etc. in the settings for the picker component as well as other ways trying other ways to grab/filter categories and am and am getting the same result. That being said I can build geometries in grasshopper with their native components and they translate to both Rhino.Inside and Revit so I know the active doc is linked.
Is there any Suggestions or advice or could this be a bug from the new installer that we updated yesterday 12/4? Along those lines, I am wondering if any one has had this issue on other versions of Revit? I am running Revit 2019.2