There is no 'AudioSource' attached Error

I am getting this error but I have audio attached to it. I have deleted the component and even rebooted. Weird issue.

So here is the error:
MissingComponentException: There is no ‘AudioSource’ attached to the “Input-Escape-MainMenu” game object, but a script is trying to access it.
You probably need to add a AudioSource to the game object “Input-Escape-MainMenu”. Or your script needs to check if the component is attached before using it.
InputEscape+c__Iterator6.MoveNext () (at Assets/Extras Created/InputEscape.cs:47)
InputEscape:Update() (at Assets/Extras Created/InputEscape.cs:40)

here is the code. It only gives the error after pressing the spacebar

using UnityEngine;
using System.Collections;
public class InputEscape : MonoBehaviour
    public GameObject mainMenuBtn;          //	quit button
    public GameObject nextBtn;			    //	next button
    public GameObject overHeadBtn;          //	overhead button

    public GameObject effectNewBestScore;

    new AudioSource audio;
    public AudioClip menuSound51;
    void Awake()
        audio = GetComponent<AudioSource>();

        mainMenuBtn = GameObject.FindWithTag("MainMenuButton");        
        overHeadBtn = GameObject.FindWithTag("OverHeadButton");
        effectNewBestScore = GameObject.FindWithTag("BestScore");

        nextBtn = GameObject.FindWithTag("NextHoleButton");
    void Update ()
        if (Input.GetKeyDown(KeyCode.Escape))
            CanvasButtonsOnOff.fire1ButtonPressed = true;


            //destroy settings-1,

    IEnumerator WaitForMainMenu2()
        audio.PlayOneShot(menuSound51, 1f);
        while (audio.isPlaying == true)
            yield return null;


Now look at the pictures:

Should it be

private AudioSource audio;


try making a public or private audioSource variable instead of new audioScource

( private AudioSource audio ; )

audio = getComponent(AudioSource) as AudioSource;


I was have this error too.
In my case maybe it happened because I add some audio files to project folder through file system.
I heard it may cause some bugs.
But, then I re import all audios it solved the problem