So, I do not give up this easily. No, I actually do nit run a scheduler.
When opening the player in offline mode (not connencted to the internet) the player is blank.
I am not able to load anything and it is not possible to shut signage player down. The point of using the player offline is that I have to since there is no internet connection available where I have to run the real presentation. Besides that forcing the player to shut down by the task manager makes it to reopen by itsself after 60sec.

Revision: I reinstalled the player on the win7 plattform. I disconnected internet after successful installation. It was not possible,to open the player without internet connection. The player won't be loaded. Thus I connected to the internet. Now the player can not find the controller. Trying to load data from the drive calls back an #3003 error (5attempts).
Loading the player.data folder message shows up that sais player will load data now. Then no player shows up. Looking into the task manager's process list there is neither an entry.