I am seeing the same issue. If I let it run for a minute, I can Alt-Tab. If I let it run for several minutes, I have to hard reboot my system.
From the log file, it has this:
------- BEGIN LEVEL LOAD INITIATED -------- Pending level = AR_0912_Engwithan_Digsite_Sublevel.
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/DebugBindings.gen.cpp Line: 51)
Cannot destroy GameObject while it's parent is being activated or deactivated.
(Filename: Line: 1560)
Unloading 3 Unused Serialized files (Serialized files now loaded: 17)
Unloading 1854 unused Assets to reduce memory usage. Loaded Objects now: 108401.
Total: 760.120422 ms (FindLiveObjects: 12.878096 ms CreateObjectMapping: 6.110727 ms MarkObjects: 729.702454 ms DeleteObjects: 11.428281 ms)
Unloading 40 Unused Serialized files (Serialized files now loaded: 17)
Unloading 3182 unused Assets to reduce memory usage. Loaded Objects now: 124646.
Total: 1366.945313 ms (FindLiveObjects: 13.786044 ms CreateObjectMapping: 5.873074 ms MarkObjects: 1344.710815 ms DeleteObjects: 2.573656 ms)
ArgumentException: The Object you want to instantiate is null.
at UnityEngine.Object.CheckNullArgument (System.Object arg, System.String message) [0x00000] in <filename unknown>:0
at UnityEngine.Object.Instantiate[GameObject] (UnityEngine.GameObject original) [0x00000] in <filename unknown>:0
at Game.ResourceManager.InstantiateObject[GameObject] (UnityEngine.Object asset, Vector3 position, Quaternion rotation, ContainerType ContainerTypeToParentUnder) [0x00000] in <filename unknown>:0
at Game.ResourceManager.InstantiateObject[GameObject] (UnityEngine.Object asset, ContainerType ContainerTypeToParentUnder) [0x00000] in <filename unknown>:0
at AudioBank.Awake () [0x00000] in <filename unknown>:0
UnityEngine.GameObject:SetActive(Boolean)
Game.RootObjectContainer:ActivateRootObject()
Game.LoadedScene:ActivateScene()
Game.SceneLoadManager:ActivateScene(LoadedScene, LoadedScene)
Game.<LoadAndSwitchToSceneWhenReadyRoutine>c__Iterator3:MoveNext()
UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
(Filename: Line: -1)
