If you recovered the computer system that VOCALOID is installed on by restoring data using a backup tool, hard disk clone, or the like, the VOCALOID authorizer will not recognize the copied data.
In this case, please uninstall all VOCALOID components and re-install them. Once you have re-installed all components, please authorize them.

Uninstalling VOCALO CHANGER PLUGIN on a Windows computer:
Click [Start] > [Settings] > [Apps] > [Apps & features] and uninstall the VOCALO CHANGER PLUGIN software.

If uninstallation fails, install the software by overwriting the existing software.