Rekordbox bug by importing from recordbox xml (version 4.5.0 on mac)?

I made my playlist in Traktor, export it to the Rekordbox xml file by RecordBuddy.

When I import a song from a playlist under the rekordbox xml tab in a Recordbox playlist the following  popup will appear:
This track already exists in the current collection. Do you want to load information in the tag of the library being imported? Beat Grid and Key information will not be loaded if the track is set locked out against analyzing. NO <-> YES
If I choose NO, nothing happens.

I have this problem a couple of weeks. Is this a Recordbox 4.5.0 bug? Or can someone help to sort out my problem?