iTunes 12.3.3.17
What happened to all my playlists. There gone after upgrading! I think that all of the music is there, maybe not.
iMac, OS X El Capitan (10.11.4)
ASC user turingtest2 help document: Empty/corrupt iTunes library after upgrade/crash - https://discussions.apple.com/docs/DOC-6561
If you don't see your content after updating iTunes - https://support.apple.com/kb/HT203225