Singleton Class Name Conflict

I just trying to create a singleton for static global variables.

public class SingletonController : MonoBehaviour {
  public static SingletonController instance { get; private set; } // <- fails
  // etc.
}

Error:
SingletonController name conflict with the class name SingletonController.
(Conflict with Assembly-CSharp-firstpass)

Unity Version2018.2.13f1

Don’t even give them the set option…

private static SingletonController instance = null;

public static SingletonController Instance
{
    get { return instance; }
}

void Awake()
{
    if (!instance)
    {
        instance = transform.GetComponent<SingletonController>();
        DontDestroyOnLoad(instance);
    }
    else
        Destroy(gameObject);
}

Thanks for response, but the set option isn’t the problem. At the moment, it seems so. Maybe a pseudo error?

See the underlined conflicts with the name. (of my first post)
126566-screen.png

Solution: Just restart Unity. If it still crying try to delete the Library folder from the project.