This happened to me the other day. Before reinstalling Roon, did you go to your library folder and label the Roon folder “old_Roon”? Go to the “Go” menu in finder while holding down the “option key” and select library. Find the folder called “Roon” and relabel it “Old_Roon” or something like that. Restart your computer. A new Roon folder should be created. You will lose all of your settings that are specific to your computer but those are quick to fix. If that does not work then delete the new Roon folder that was created (keep the old_Roon folder) and reinstall Roon. This is what I ended up doing after Roon froze on my iMAC but aside from having to re-do some settings, I haven’t had any issues on my iMac since then.