There appears to be a limit on the number of playlists supported in the Android app. The bug manifests itself by causing Spotify to crash on startup leaving the user no choice, but to wipe the app and all sync'ed data, remove the additional playlists from a desktop app then re-install and re-sync. It's been around for over a year and has even been acknowledged by a Spotify employee. Sort it out.
These might be also the same problem: