Error when importing in Unity 2019.3.7f1 (m_NaturalOrientation of ProxyNode not assigned)

[piede828]

I get this error when trying to install the editor:
UnassignedReferenceException: The variable m_NaturalOrientation of ProxyNode has not been assigned. You probably need to assign the m_NaturalOrientation variable of the ProxyNode script in the inspector. UnityEngine.Transform.get_position () (at <d815b7efac424eeb8e053965cccb1f98>:0) UnityEditor.Experimental.EditorVR.Proxies.ProxyNode.GetFacingDirection (UnityEngine.Vector3 cameraPosition) (at Assets/EditorXR/Scripts/Proxies/ProxyNode.cs:548) UnityEditor.Experimental.EditorVR.Proxies.ProxyNode.Update () (at Assets/EditorXR/Scripts/Proxies/ProxyNode.cs:501)

[amirebrahimi]

Did you clone using these instructions?
Did you try a re-import of the whole project? Sometimes this fixes missing references.