Can't sync local files to iPhone

[Carl_I]

I'm having trouble getting local MP3 files on my laptop to sync onto my iPhone.

The files play perfectly on Spotify on my laptop, but after sync when I try to play them on my iPhone I just get the notice saying "Track not synced".

The strange thing is that one year ago this worked fine - with the very same files! Also, a newer MP3 file that I synced just a couple of months ago plays perfectly on my phone.

What could be the reason that the older files won't play like they did before? I've tried copying and pasting and putting into new folders, but nothing works.

[Adam]

Is it specific tracks that aren't syncing or is it all new files you try to sync that aren't working? When you sync the local files, is your iPhone showing up under Devices inside Spotify?