As of Engine DJ v2.0, Crates and Playlists have merged into a single list type — Playlists. Engine DJ Playlists offer the best aspects of both list types. 

During the migration upgrade process, your Crates will be converted into Playlists preserving all the content and structure. Now with Playlists, you can freely rearrange the lists within the collection tree and also the tracks within them.