Starting macOS Catalina and later, the Guitar-2-Bass Modulator audio unit and VST plug-in won’t work natively. You will need to wrap the 32-bit version inside any 64-bit converter for digital audio workstations using additional software (specially on Big Sur and onwards). Keep in mind six years have passed since its release on 2015, so no online support will be offered anymore. You can now download it for free!