NoSuchMethodError: the method 'toRawHandle' was called on null. about flutter_workmanager HOT 3 CLOSED

Note: This happens only on VSCode.
Android Studio starts the app (but my task is never triggered).

Continuing after the first error:

Exception has occurred.
PlatformException (PlatformException(1, You have not properly initialized the Flutter WorkManager Package. You should ensure you have called the 'initialize' function first! Example: 

`Workmanager.initialize(
  callbackDispatcher,
 )`

The `callbackDispatcher` is a top level function. See example in repository., null))

BTW, I've inserted this on my App.kt file: Log.d("WorkmanagerPlugin", "WorkmanagerPlugin is initializing") and this log appears on catlog when the app is initialized (before Flutter first frame is rendered and the bug manifests itself).

After running a couple of times (and moving this initialization first thing in my flutter main), the first error doesn't occur anymore, but the second remains:

I also have to write this: WidgetsFlutterBinding.ensureInitialized();, otherwise, my app says:

Exception has occurred.
FlutterError (ServicesBinding.defaultBinaryMessenger was accessed before the binding was initialized.
If you're running an application and need to access the binary messenger before `runApp()` has been called (for example, during plugin initialization), then you need to explicitly call the `WidgetsFlutterBinding.ensureInitialized()` first.
If you're running a test, you can call the `TestWidgetsFlutterBinding.ensureInitialized()` as the first line in your test's `main()` method to initialize the binding.)

from flutter_workmanager.

Is your callbackDispatcher a top level function?
Can you provide me with a sample that demonstrates this behaviour?

from flutter_workmanager.

That was the problem. Moving the function to public and outside the class made it work.

from flutter_workmanager.