why does my playlist not play

[gmicky]

Hi There

I can't understand why my playlist won't play on my Echo Dot, I have premium, the problem is this:  When I'm on the Spotify app on my laptop most songs will play both on my laptop and on my Dot, when I try and play a song form my local files they play on my laptop but the dot option is greyed out I've converted the files from the CD I'm trying to play to MP3 but still have no joy. Any ideas