It seems, that len(self.__random_files) - 1) always has only 2 digits. I have emailed you this. I have to setup my SDK again to debug this. Edit: I have got my SDK running again. I added a print len(self.__random_files) - 1 to the code. It starts always with 60. If I play other contend, and readd the playlist again, then the values are correct (more than 1000). Something lets the list decrease to only 60 items.