SD card error

I’ve had my Clip Sport for less than a year - today it froze up after getting a low battery notice and I had to hold down the center button and arrow for 20-30 seconds to get it to reboot. Since then, it’s giving me an error on my SD card, saying “Disk Error! Please replug SD card”. All my music is stored on my SD card (Sandisk Ultra 16 gig) and I’ve been using it with no issues for months. I have tested the card in another device and it appears to be working fine. Nothing has changed except for that freeze-up. Any suggestions?

I forgot to mention, I also tried another card in the Clip Sport and got the same error. Ugh.

What happens when you turn the player on without the SD card in it?