Hi Mirko, I think I know what your problem is.
You are probably compiling with the HTML Folder as the <project>-export folder, right?
This is correct, but you have to make sure that your <project>.html file is renamed to index.html. Doing this solved the issue for me, now the App knows where to start.
Hope it helps.
-Edit
I just realized how old this is, Mirko probably won’t read this anymore. However, the solution is posted.