"File format not supported" when they worked before, urgent

Hi,

I have all of my tracks on my hard drive and it has been working well with rekordbox so far, but all of a sudden I got this red symbol and it says the file format is not supported on all tracks I imported before a specific date, even though I've done nothing to change the file path or so. They were all working yesterday. The tracks work when I re-import them but it seems like I have to do that 1 by 1 (by removing the track and adding it again) and that will take ages. But that clearly means there is nothing wrong with the file format.. This is soooo frustrating!!!!! Can someone please help? There must be a way around this right? Is there a way to relocate the tracks? (I don't get the option now). Otherwise I have to reimport all the tracks again and reorganise them into all the different sub-categorised playlists I have and that's going to take soooo long. My playlists are backed up to rekordbox due to my subscription but I dont know what difference that makes when my files are still on the harddrive..

It's possible that it happened today after I selected all my tracks and analysed them because I wanted rekordbox to analyse the key..it worked for a moment and suddenly I started getting this red error.

I even have a rekordbox creative subscription and have been meaning to upload all of my tracks to the cloud but I didn't get around to doing it yet because for some reason it's not recognising my dropbox upgrade yet.

I'm using rekordbox 6.6.3 This is the third time I have to re-import all my tracks because of file errors.. and it's really painful! Last time it was due to missing files, but then it worked well for a long time after I fixed it. This problem is completely new..

Please and thank you!! <33