SD Card Question

[Pedrödelabongo]

I have all my music on an 32GB card and, until yesterday, it worked great, - but after I put some more tunes on it and stuck it back in the car, the system is scrolling through the songs telling me that each one is damaged.
I have a Mac, so had to convert the songs from iTunes (AAC format) to MP3 so what's occurring and what do I need to do to get it working again?

 

[mcwharam]

Not sure with Mac but Windows OS will scan and check the SD card for errors and fix without having to do a reformat. Wortha try if you have a card reader and access to a windows PC/ laptop etc.

If not and will be a right pain, but I would back up all the music elsewhere and then do a format on the card and reload the music back on. Takes a while transferring up to 32GB back and forwards.