Hello! Are your using a Mac machine perchance?
If that's the case, we're really sorry to say that the current demo won't run on Mac Catalina (OS 10.15+) and sometimes not on Mojave (10.14).
We will try to upgrade the demo as soon as we can >_<" However, that would require a Mac machine, which we don't have on hand at the moment. We will definitely post an update once that's taken care of though!