Simple keyboard input not working. Why?,Simple code for keyboard input getting warning...Why?

The simple code below produces a warning “Asseration failed: App thread is looking for a frame (0) which was not yet create” one time. Then the IF statement does not respond to a key depression for the up arrow. I’m new to Unity so I appreciate all help.
Thx
Bob G.

CODE:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class KeyBdInput01 : MonoBehaviour {

// Use this for initialization
void Start () {
    Debug.Log("Start");
}

// Update is called once per frame
void Update () {
    Debug.Log("Update");
    if (Input.GetKeyDown(KeyCode.UpArrow)) 
    {
        Debug.Log("Up Arrow Pressed");
    }
	
}

}
IMAGE:

,The code below is producing a warning “Assertion failed: App thread is looking for a frame (0) which was not yet created” one time. The IF statement gets no response to an up arrow key depression. A screen shot of this simple scene and simple code is shown below.
All help is greatly appreciated. I’m new to Unity.


Thx
Bob G.
CODE:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class KeyBdInput01 : MonoBehaviour {

// Use this for initialization
void Start () {
    Debug.Log("Start");
}

// Update is called once per frame
void Update () {
    Debug.Log("Update");
    if (Input.GetKeyDown(KeyCode.UpArrow)) 
    {
        Debug.Log("Up Arrow Pressed");
    }
	
}

}

Have you clicked onto the game view to give it focus?

Toby…of course. Many times.

I'm now certain that something is wrong with my Project setup which produces the warning "Asseration failed: App thread is looking for a frame (0) which was not yet create".  

If anyone has seen that warning before and knows of a possible cause, please let me know.

I have worked around this problem by starting from scratch with a new Project. No such issue with the new project so I’m going to move on. However, it would be nice to know of common causes of the warning above if anyone has experienced that.

Cheers,
Bob G