So here's my theory: The reason the fixes are different is because these are all related to corrupt storage. Clearing preferences rewrites the preferences, fixing this, formatting your SD if the media files there are corrupt fixes this, clearing data on Play Music/Books/Movies etc, same deal. Whatever app you have that is trying to grab cached data pukes when it hits the corrupt file/setting. I had cascading errors with gapps, media and framework and did a workaround by disabling Media Storage and DRM protected storage, but then you can't use your apps with files on the SD card. -But that tells me it's storage (somewhere), so I re-enabled storage and DRM, then went into Apps>All and went to all of the Google Play apps and cleared the data for each one (this doesn't get rid of your pictures or music on your SD...) and this seems to have fixed the issue for me.