unity Coroutine couldn't be started because the the game object 'ModelsScene' is i

This error message in Unity usually occurs when you try to start a coroutine on a GameObject that is inactive or has been destroyed.

To fix this issue, you should first check if the GameObject 'ModelsScene' is active and not destroyed. If it is destroyed or inactive, you can use the `GameObject.Find` method to get a reference to a new instance of the object, if it exists.

Here's an example of how you can modify your code to handle this error:

public GameObject modelsScene;

void Start()
{
    StartCoroutine(MyCoroutine());
}

IEnumerator MyCoroutine()
{
    // Check if the modelsScene object exists and is active
    if (modelsScene != null && modelsScene.activeInHierarchy)
    {
        // Your coroutine code here
        yield return new WaitForSeconds(2.0f);
    }
    else
    {
        Debug.LogError("The modelsScene object is invalid or inactive.");
    }
}

By checking if the `modelsScene` object is valid and active before starting the coroutine, you can avoid the error message you were experiencing.