I downloaded 3 sets. One set includes also one pbf file, everything works well (THE_MOST_POPULAR_COVER_SONGS_OF_ALL_TIME_VOL4)
The next two (Ballad drum set and vintage drum set) just consist of PDF and a *drm file. With this drm files I can´t do anything.
What can I do, where is the prolem - how can I get the pbf file that everything works well?