Following is the call stack for the null reference exception:

NullReferenceException: Object reference not set to an instance of an object
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:520)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:692)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:701)
FMODUnity.EventReferenceUpdater+<SearchGameObject>d__37.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:337)
FMODUnity.EventReferenceUpdater+<SearchPrefabs>d__34.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:230)
System.Linq.Enumerable+ConcatIterator`1[TSource].MoveNext () (at <cb140ef12a6a42429eb3231fc502b0c6>:0)
FMODUnity.EventReferenceUpdater.UpdateProcessing () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:1761)
UnityEditor.EditorApplication.Internal_CallUpdateFunctions () (at <308d48a21a3e462ba091bd758b25b1e6>:0)


Following is the call stack for the stack overflow exception:

StackOverflowException: The requested operation caused a stack overflow.
System.Collections.Generic.List`1[T].System.Collections.Generic.IEnumerable<T>.GetEnumerator () (at <6d53f1ee8ee746e4b3c819c68e33f296>:0)
System.Linq.Enumerable.Any[TSource] (System.Collections.Generic.IEnumerable`1[T] source) (at <cb140ef12a6a42429eb3231fc502b0c6>:0)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:672)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:692)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:701)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:692)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:692)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:692)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:692)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:692)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:692)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:692)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:692)
FMODUnity.EventReferenceUpdater+<GetGenericUpdateTasks>d__45.MoveNext () (at Assets/Plugins/FMOD/src/Editor/EventReferenceUpdater.cs:692)

(and is just stuck at MoveNext for the rest of the stack until the overflow)