Comentário oficial
Salut,
You can move from v3 to 5 without issue, the database will translate all of your tracks, however you may want to re-analyse to take advantage of improved analysis and newer functions.
The license you received with your CDJs was for rekordbox 2 and that license requirement was removed for rekordbox as of v3. When rekordbox 4 was released, introducing the performance mode, a license was required to unlock that functionality, but none is needed for EXPORT mode (the organization mode of rekordbox, similar to all prior versions). Unfortunately that old license is not compatible with rekordbox 4 or 5, and if you want to use the performance functions, you must purchase one - but you can use a 30 day free trial before doing so.