I was using Traktor 3.5.3 and have moved onto Traktor 4.0.2. Upon starting TP4 it imports all the settings etc and my collection is there, but my playlists are empty. I have tried creating them anew but when closing TP4 it says "saving collection', I then reopen TP4 and the collection is there but all the playlists are again completely empty. In Traktor 3.5.3 the playlists always saved automatically and never had this issue. Any suggestions welcome as I have searched around for resolutions but to no avail. I am using a 2015 MBP 15".