The type or namespace name 'MultiAimConstraint' could not be found

I am struggling to find out why this code throws this error:

The type or namespace name ‘MultiAimConstraint’ could not be found

```csharp
*using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor.Animations.Rigging;

public class HeadLook : MonoBehaviour
{

private MultiAimConstraint mac;
void Start()
{
    mac = GetComponent<MultiAimConstraint>();
}

// Update is called once per frame
void Update()
{
   
    float inputVertical = Input.GetAxis("Vertical");
    mac.weight = inputVertical;
}

}*
```

It’s not complete code so ignore what it is trying to do. Just can’t get rid of the error.
Yes I have added Animation Rigging in the package manager.

Thanks

same here =(

its crazy that this was working minutes ago… suddendly it stopped working.

PS.: UnityEditor.Animations.Rigging must be UnityEngine.Animations.Rigging