Hi summer_goth,
Yes, I'm afraid to say there has been a small API change. Now, the onInit method receives 3 parameters.
We've added the main panel, so you are able to build your panel hierarchy there.
Probably, what is happening, is that the Application class is calling an empty onInit method (with 3 parameters) instead of your onInit method (with 2 parameters).
Please let me know if this solved the problem.
Best regards,
Sergio.