This error message is output from your (windows) OS.

It is because the audio device driver in your machine is occupied by another program which conflicts with VOCALOID3 Editor and Tiny VOCALOID3 Editor, or there is a problem in audio device driver, causing the tool unable to call the device.

Please shut down any other application and any resident program before launching VOCALOID3 Editor, or try updating the audio device driver to the latest version.