Clio 200 MP3 playback

Hi

I've burned 3 CDs with MP3s in folders. Each time my headunit just spits the disc out with an error message. I thought the standard 200 headunit (with bluetooth) played MP3 CDs?
 
I haven't used a CD in years!

Have you tried it without having them in folders on the disc? May be worth trying?

Disclaimer: I know absolutely nothing about MP3 CDs!