Most Reanimated 11,010 bugs come from forgetting which runtime a line runs on. The first version of Worklets and the UI Thread's demo called scheduleOnRN(console.log, ...) inside a worklet, and Metro printed:
ERROR [Error: Exception in HostFunction: [Worklets] Locally defined function passed to ...
It goes on: "Only functions defined on the RN Runtime or host functions can be scheduled." In a worklet, console is the UI runtime's copy. Scheduling a module-level say() that calls console.log fixed it. Also watch for:
Reading .value during render. It never triggers a re-render; render from React 7,897 state.
Calling a plain helper from a worklet. It needs the 'worklet' directive too.
Capturing large objects. Everything a worklet references is copied to the UI runtime.
Mismatched versions. Let npx expo install choose, and rebuild the development build after upgrading.
Forgetting GestureHandlerRootView, which makes gestures do nothing.