Q. When playing back a song, a dialog box indicating an undefined error appears, and the song cannot be played back.
This problem occurs when VOCALOID4 Editor cannot use your audio device due to "the device being occupied by some other application" or similar reason.
Exit other applications and memory-resident programs that are running, and then restart VOCALOID4 Editor.
When playing back a song, a dialog box indicating an undefined error appears, and the song cannot be played back.