Mp4 player. I made a mistake and deleted the files on my mp4 player and now it will not let me

Question

I made a mistake and deleted the files on my mp4 player and now it will not let me download anything on it.Same problem as Bandjo's, used the delete all and now it will not allow me to download any files to the MP4 player. Error messge is, Cannot create or rplace "name of file": the directory or file cannot be created. Wall un successful in creating a directory for MP3.

normsbackup