Bug NullReferenceException in GraphicRaycaster.Raycast

While running a standalone build, the internal GraphicRaycaster.Raycast will occasionally begin spamming NullReferenceExceptions related to mouse input every frame. This effectively shuts down the UI EventSystem, and makes it impossible to interact with the game. It occurs rarely enough to be difficult to reproduce, but often enough to be a significant problem (we've noticed about 3% of our users experiencing the error in recent beta tests). There's no common behavior associated with consistently producing the error, and as it's engine's code we can't debug it further. We've noticed two similar but slightly distinct stack traces when experiencing this problem:

1)
UnityEngine.UI.GraphicRaycaster.Raycast (UnityEngine.Canvas canvas, UnityEngine.Camera eventCamera, UnityEngine.Vector2 pointerPosition, System.Collections.Generic.IList`1[T] foundGraphics, System.Collections.Generic.List`1[T] results) (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.UI.GraphicRaycaster.Raycast (UnityEngine.EventSystems.PointerEventData eventData, System.Collections.Generic.List`1[T] resultAppendList) (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.EventSystems.EventSystem.RaycastAll (UnityEngine.EventSystems.PointerEventData eventData, System.Collections.Generic.List`1[T] raycastResults) (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.EventSystems.PointerInputModule.GetMousePointerEventData (System.Int32 id) (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.EventSystems.StandaloneInputModule.ProcessMouseEvent (System.Int32 id) (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.EventSystems.StandaloneInputModule.ProcessMouseEvent () (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.EventSystems.StandaloneInputModule.Process () (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.EventSystems.EventSystem.Update () (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)

2)
UnityEngine.Component.GetComponent[T] () (at <047294ce45cf4b9a9441e48d2b8435e4>:0)
UnityEngine.UI.Graphic.get_canvasRenderer () (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.UI.GraphicRaycaster.Raycast (UnityEngine.Canvas canvas, UnityEngine.Camera eventCamera, UnityEngine.Vector2 pointerPosition, System.Collections.Generic.IList`1[T] foundGraphics, System.Collections.Generic.List`1[T] results) (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.UI.GraphicRaycaster.Raycast (UnityEngine.EventSystems.PointerEventData eventData, System.Collections.Generic.List`1[T] resultAppendList) (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.EventSystems.EventSystem.RaycastAll (UnityEngine.EventSystems.PointerEventData eventData, System.Collections.Generic.List`1[T] raycastResults) (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.EventSystems.PointerInputModule.GetMousePointerEventData (System.Int32 id) (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.EventSystems.StandaloneInputModule.ProcessMouseEvent (System.Int32 id) (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.EventSystems.StandaloneInputModule.ProcessMouseEvent () (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.EventSystems.StandaloneInputModule.Process () (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)
UnityEngine.EventSystems.EventSystem.Update () (at <0b05dff53c1b4e478fedc6053f8a30c9>:0)

Anyone else ran into this problem and found a way to work around it (or even just to consistently reproduce it)?

 

Seems to be similar (tho not exactly the same) as this reported issue: https://forum.unity.com/threads/missingreferenceexception-in-graphic-raycaster.1053221/#post-6810110

No response from Unity.

 

I have same problem and no idea what is causing this error