Scarlett Plug-in Suite is no longer under development support, meaning we cannot provide any further updates to support macOS Catalina or future versions of macOS or Windows.
Scarlett Plugin Suite will continue to function as expected on macOS 10.14 Mojave and below and may work beyond this, though this won't be tested.
The latest version of Windows that Scarlett Plugin Suite was tested on is Windows 10 build 1809, again it's possible that the Scarlett Plugin Suite will continue to work on newer versions of Windows, however, this will not be tested.