Hello @Gogo and welcome,
not sure what this is exactly, another user was having an error during install because his OneDrive folder was activated and locking a folder, preventing the installer from working properly.
You can have a look here: https://forum.scalerplugin.com/t/can-not-install-scaler2/3640/2
Otherwise, check if there is anything running on your computer that could conflict with the installer.