I notice that on the Xojo download page requirements section, Yosemite and El Capitan are listed but Catalina is not.
Catalina should be listed and Yosemite and El Cap should be deleted - Xojo does not work with <10.12 macOS.
I am sorry to say that I am stuck right now unable to update my clients. I've had to do a lot of work on some apps to move to r2 in order to build for Catalina - but now dragging is broken in 10.10 and 10.11.
Xojo, I need a quick fix. Do I wait or do I ship?