Why can't I play the audio files in the Klett Sprachen App? 05 February 2026 15:45 Updated The volume might be turned off. Check to make sure the loudspeaker volume is on. Related articles How can I play the audios for my book in allango? Can I play media files in the Klett Sprachen App? Why is the Klett Sprachen App not working? What is the Klett Sprachen App? Where can I find the allango licence key?