I am trying to embed a Flutter module into iOS app.
But when i tap the button that will show the FlutterViewController, a blank screen shows up and this is printed on the console:

```
Failed to find assets path for "flutter_assets"
[VERBOSE-2:engine.cc(111)] Engine run configuration was invalid.
[VERBOSE-2:FlutterViewController.mm(462)] Could not launch engine with configuration.
flutter: Observatory listening on http://127.0.0.1:54632/

```

* I followed this tutorial <https://github.com/flutter/flutter/wiki/Add-Flutter-to-existing-apps>
* I added a FLUTTER\_ROOT to my build settings
* I tried running the app with a `FlutterAppDelegate` and also a `FlutterViewController`
* My `flutter doctor` says nothing is wrong.