Hello, this is one of the latest bugs that appeared in CopyTrans Manager, it occurs because CopyTrans Manager shows cloud tracks in the interface, but the music is not actually on your device. For a temporary fix, CopyTrans Manager and go to More -> Settings -> Advanced settings. Then find parameter main.show_cloud_tracks and set the value to "no". After that, try connecting your device again.

We are aware of the issue and will attempt to fix it in the next version of the program.