I got the same thing. Beach ball hangs after a few seconds. I’ve been having an issue related to VDMX integration with Vuo so I tested several things.
VDMX won’t load any Vuo compositions made with newer versions than 2.1.2. but as you might know, Vuo 2.1.2 doesn’t work property in Big Sur. And if you have Vuo newer than 2.1.2 installed on your Mac, VDMX won’t respond no matter what version of your Vuo composition. It just simply doesn’t work. For now, it seems the only way to walk around is exporting Vuo composition to FFGL plugin.
It’s been over 5 months since Vuo 2.2.0 has released, 8 months since the first Big Sur beta. VDMX needs an update.