After the installation of UnityEngine.Monetization was automatically changed project. The solution open in VS 2017 Community. Now the decision is not one project but 3: MyProject, MyProject.Editor, MyProject.Plugins. Now unity complains for the line using UnityEngine.EventSystems; (the type or namespace name "EventSystems" does not exist in the namespace "UnityEngine"). Besides that there was error in the line "GetComponent()"(could not find Image) and a lot of the same mistakes. What is the problem here?