Can't sync music files to my Clip+ :(

I can’t seem to sync / drag and drop files onto my new clip+, it either says “sync failed” or “copying” and then never finishes D:

I checked it’s up to date and that the file was mp3

Assuming you have tried al USB ports of your computer probably you can try to switch the Sansa on MSC mode (Settings > System Settings > USB mode > MSC).