I think I have figure out one error.
I can’t add the files to the playlist from Collection because it’s a video file (mp4). When I go to VIDEO -> All Videos, then i can add it to a playlist i have created under VIDEO -> Video Playlists.
I still found the mp4 files under Collection, but I can only add mp3 to PLAYLISTS.
Do you understand how i mean?
I guess you need to have check to see if it’s a MP4 or MP3 and then create the playlist in right “group”.