TypeError: Cannot read property 'initialize' of null

[KingCosmic]

I'm following just the GitHub starter code to try and get my rive asset to run my animation and am running into this error on a blank slate of create-react-app, I've tried looking into the source code to find a solution and so far have found nothing.

[neio-dev]

Faced the same error. It seems to be an issue with masks.
ClipPath aren't working too, canvas loads but they still are rendered outside the clip

In Chrome :

In Rive :

[calv-io-n]

Also having this problem as well with masks