Could be a combo of XCode 12.5 and RN 0.61.5: https://github.com/facebook/react-native/issues/28405 I see the Helix doc specifies that RN version implicitly in the "Getting Started": npx [email protected] init MyApp I see some hacks offered to save 0.61.5 usage, but do you think Helix can move up to RN 0.64? I'll see if that at least changes the error. 🙂

And now the Krell reagent example has stopped working. Installing new XCode 12.5.1 now.

helix should work with any version of React > 16

Yeah, I got nowhere upgrading or downgrading XCode etc. I even had the Krell Reagent example stop working! Right now this works: https://github.com/PEZ/rn-rf-shadow

Got this working on (incidentally) my Intel MBP: https://github.com/aiba/helix-react-native Moved shadow and helix versions current, replaced react-native with a fresh one, and had to do a pod install step to pick up FBReactNativeSpec 0.64.2 Moving back to the M1 to confirm not an issue.