So finally I did it. The Bug is gone and we are now ready for public testing (You might want to call it beta :-) ).
For those who are curios: I removed an additional package, of which I thought was unnecessary. It turns out it had an additional dependency, which is used to create menu entries. And since it was not available, there where no menu entries.
And now I am out of here, the sun is shining and it is warm outside. So please stay patient with me.