Three points from discussion in https://github.com/reactjs/react-redux/issues/756:

* Due to https://bugs.chromium.org/p/chromium/issues/detail?id=701371, environments like CodeSandbox show `Error: null` in our “React caught an error” warning. Let’s consider skipping both as they’re not very useful and look like a bug. `Error: null` looks like a separate error and draws attention away from the real error just above.

* In any case we should probably not print `The error was thrown at:` if we don’t have a JS stack.

* There is a related issue. What do we pass to error boundary if we caught `null`? It seems that most error boundaries will intuitively do something like `if (this.state.error)` or read `error.message`, which `null` will break. There are other falsy values too like `''` and `undefined`. My proposal is we always wrap primitives into our own `Error` objects that we pass to the boundary.
const logError = showDialog(capturedError);
  
  
  if (logError === false) {
    return;
  }
  const error = (capturedError.error: any);
  
  let message;
  let name;
  let stack;
  if (
    error !== null &&
    typeof error.message === 'string' &&
    typeof error.name === 'string' &&
    typeof error.stack === 'string'
  ) {
    message = error.message;
    name = error.name;
    stack = error.stack;
  } else {
    
    message = '' + error;
    name = 'Error';
    stack = '';
  }