Rekordbox is not anymore able to analyze tracks and I don't know why.

Hi everyone, I have a big issue with rekordbox. 

Last day, without any kind of reason, rekordbox started to be not able to analyze tracks.

In particular, I drag and drop my new downloaded tracks in the rekordbox collection (like I have always did), but but a screen appears with the text " Some imported tracks cannot be played because they are not supported by CDJ/XDJ) " (i translated it from my language). Moreover, the tracks are imported, without the possibility to play them and with the red prohibition sign at the beginning of the file name. It's of course a bug, because they are original tracks bought on original platforms and I tried with many formats.

Please, try to help me. 

This problem came up suddenly. Without changing any settings.
Version of rekordbox 7.0.2. 

Thanks in advance