I have sent you Crash Log via PM, it's strange this bug, It has started for 3 days
The only thing I found is a confirmation that they seem to be using AAC exclusively: https://support.spotify.com/us/article/audio-quality/That one specifies AAC for the web player, and is silent on what format is used in the other clients.
i'd need to know what's broken so i can test for the particular problem, however a fuzz tester may come in handy also - thanks for mentioningNot sure if what I have here qualifies (since I don't know what's broken), but: recently I got a (previously valid) broken FLAC and MP3 file caused by some choking, or hardware cell damage, when I copied those files from an SD card. I can't share them here since they are more than 30 seconds long (and that would violate the forum's ToS), so I'll try to get them to you in other ways.
create subdirectories with variables like \%artist%\%album%\This should work, so you'll need to tell us more about what you are trying to do.