Added this package to Unity project from Git URL, then tried to add the ADSR Envelpope.cs script to an obect and was shown this message; "Can't add script component "ADSR Envelope" because script ...

RATSceneSetup" I work with Unity 2018.4.18f1 (64-bit) and Visual Studio 2019 first of all, i can't add the script via the "Add component" button of my empty object named MyRoom in the inspector ...