Script gone on Runtime

I have a GameObject in the public of one of my scripts, however when I run the game it disappears. I can put the GameObject back in after the game is already running and it works fine.

Before Run:
200987-screenshot-2022-10-20-203008.png

While Run:
200988-screenshot-2022-10-20-203040.png

If anyone could help that would be great!
Thanks!

Edit: On runtime I get this Error

NullReferenceException: Object reference not set to an instance of an object
UnityEditor.Graphs.Edge.WakeUp () (at <8e8a32ebae4d4c768ca69b7e552734c1>:0)
UnityEditor.Graphs.Graph.DoWakeUpEdges (System.Collections.Generic.List1[T] inEdges, System.Collections.Generic.List1[T] ok, System.Collections.Generic.List`1[T] error, System.Boolean inEdgesUsedToBeValid) (at <8e8a32ebae4d4c768ca69b7e552734c1>:0)
UnityEditor.Graphs.Graph.WakeUpEdges (System.Boolean clearSlotEdges) (at <8e8a32ebae4d4c768ca69b7e552734c1>:0)
UnityEditor.Graphs.Graph.WakeUp (System.Boolean force) (at <8e8a32ebae4d4c768ca69b7e552734c1>:0)
UnityEditor.Graphs.Graph.WakeUp () (at <8e8a32ebae4d4c768ca69b7e552734c1>:0)
UnityEditor.Graphs.Graph.OnEnable () (at <8e8a32ebae4d4c768ca69b7e552734c1>:0)

I found out the problem, I restarted Unity and it just went away.