Crash on toggling streaming level visibility

I’m working with streaming levels on my current project. I’m having an issue where, for some reason, a sublevel I’m streaming in has a bunch of actors at the wrong locations (it looks like this when opened by itself, but like this when viewed in the persistent level). In troubleshooting that, I found that I also can’t toggle that level’s visibility, or remove that level from the persistent level, without the engine crashing.

Below is my log from my crash just after I tried to remove the level. Help meeeee. (Sublevel is S_Hub_Industry, persistent level is S_Hub_Main).

[2016.10.07-03.12.49:955][683]MapCheck: New page: Map Check
[2016.10.07-03.12.49:955][683]LightingResults: New page: Lighting Build
[2016.10.07-03.12.50:008][683]LogReferenceChain: Searching referencers for S_Hub_Industry. This may take several minutes.
[2016.10.07-03.12.50:671][683]LogReferenceChain: Generating reference graph ...
[2016.10.07-03.12.50:688][683]LogReferenceChain: Level 0 has 2 nodes ...
[2016.10.07-03.12.50:731][683]LogReferenceChain: Level 1 added 4 nodes ...
[2016.10.07-03.12.50:772][683]LogReferenceChain: Level 2 added 3 nodes ...
[2016.10.07-03.12.50:817][683]LogReferenceChain: Level 3 added 1 nodes ...
[2016.10.07-03.12.50:864][683]LogReferenceChain: Level 4 added 2 nodes ...
[2016.10.07-03.12.50:906][683]LogReferenceChain: Level 5 added 4 nodes ...
[2016.10.07-03.12.50:950][683]LogReferenceChain: Level 6 added 4700 nodes ...
[2016.10.07-03.12.50:999][683]LogReferenceChain: Level 7 added 13768 nodes ...
[2016.10.07-03.12.51:050][683]LogReferenceChain: Level 8 added 17267 nodes ...
[2016.10.07-03.12.51:098][683]LogReferenceChain: Level 9 added 1437 nodes ...
[2016.10.07-03.12.51:143][683]LogReferenceChain: Level 10 added 2 nodes ...
[2016.10.07-03.12.51:187][683]LogReferenceChain: Level 11 added 0 nodes ...
[2016.10.07-03.12.51:187][683]LogReferenceChain: Generating reference chains ...
[2016.10.07-03.12.51:188][683]LogReferenceChain:   
[2016.10.07-03.12.51:188][683]LogReferenceChain: External Referencers:
[2016.10.07-03.12.51:188][683]LogReferenceChain:   
[2016.10.07-03.12.51:188][683]LogReferenceChain: (root) (standalone) World /Game/Maps/S_Hub_Main.S_Hub_Main->CurrentLevel
[2016.10.07-03.12.53:917][683]LogReferenceChain:   Level /Game/Maps/S_Hub_Main.S_Hub_Main:PersistentLevel->UE4Editor-Engine.dll!ULevel::AddReferencedObjects() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\level.cpp:286]
[2016.10.07-03.12.53:917][683]LogReferenceChain:     LightingSystemSwitcher_C /Game/Maps/S_Hub_Main.S_Hub_Main:PersistentLevel.LightingSystemSwitcher_116->CallFunc_CreateDynamicMaterialInstance_ReturnValue3
[2016.10.07-03.12.53:917][683]LogReferenceChain:       MaterialInstanceDynamic /Game/Maps/S_Hub_Industry.S_Hub_Industry:PersistentLevel.Torch_1052.LPVAreaLight.MaterialInstanceDynamic_312->Outer
[2016.10.07-03.12.53:917][683]LogReferenceChain:         (PendingKill) StaticMeshComponent /Game/Maps/S_Hub_Industry.S_Hub_Industry:PersistentLevel.Torch_1052.LPVAreaLight->Outer
[2016.10.07-03.12.53:917][683]LogReferenceChain:           (PendingKill) Torch_C /Game/Maps/S_Hub_Industry.S_Hub_Industry:PersistentLevel.Torch_1052->Outer
[2016.10.07-03.12.53:917][683]LogReferenceChain:             (PendingKill) Level /Game/Maps/S_Hub_Industry.S_Hub_Industry:PersistentLevel->Outer
[2016.10.07-03.12.53:917][683]LogReferenceChain:               (target) World /Game/Maps/S_Hub_Industry.S_Hub_Industry
[2016.10.07-03.12.53:917][683]LogReferenceChain:   
[2016.10.07-03.12.53:917][683]LogReferenceChain: (root) CrowdManager /Game/Maps/S_Hub_Main.S_Hub_Main:NavigationSystem_0.CrowdManager_0->Outer
[2016.10.07-03.12.53:917][683]LogReferenceChain:   NavigationSystem /Game/Maps/S_Hub_Main.S_Hub_Main:NavigationSystem_0->AbstractNavData
[2016.10.07-03.12.53:917][683]LogReferenceChain:     AbstractNavData /Game/Maps/S_Hub_Main.S_Hub_Main:PersistentLevel.AbstractNavData-Default->Outer
[2016.10.07-03.12.53:917][683]LogReferenceChain:       Level /Game/Maps/S_Hub_Main.S_Hub_Main:PersistentLevel->UE4Editor-Engine.dll!ULevel::AddReferencedObjects() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\level.cpp:286]
[2016.10.07-03.12.53:917][683]LogReferenceChain:         LightingSystemSwitcher_C /Game/Maps/S_Hub_Main.S_Hub_Main:PersistentLevel.LightingSystemSwitcher_116->CallFunc_CreateDynamicMaterialInstance_ReturnValue3
[2016.10.07-03.12.53:917][683]LogReferenceChain:           MaterialInstanceDynamic /Game/Maps/S_Hub_Industry.S_Hub_Industry:PersistentLevel.Torch_1052.LPVAreaLight.MaterialInstanceDynamic_312->Outer
[2016.10.07-03.12.53:917][683]LogReferenceChain:             (PendingKill) StaticMeshComponent /Game/Maps/S_Hub_Industry.S_Hub_Industry:PersistentLevel.Torch_1052.LPVAreaLight->Outer
[2016.10.07-03.12.53:917][683]LogReferenceChain:               (PendingKill) Torch_C /Game/Maps/S_Hub_Industry.S_Hub_Industry:PersistentLevel.Torch_1052->Outer
[2016.10.07-03.12.53:917][683]LogReferenceChain:                 (PendingKill) Level /Game/Maps/S_Hub_Industry.S_Hub_Industry:PersistentLevel->Outer
[2016.10.07-03.12.53:917][683]LogReferenceChain:                   (target) World /Game/Maps/S_Hub_Industry.S_Hub_Industry
[2016.10.07-03.12.54:587][683]LogWindows: Windows GetLastError: The operation completed successfully. (0)
[2016.10.07-03.12.55:426][683]LogCrashTracker: 


[2016.10.07-03.12.55:426][683]LogCrashTracker: 


[2016.10.07-03.12.55:426][683]LogWindows:Error: === Critical error: ===
[2016.10.07-03.12.55:426][683]LogWindows:Error: 
[2016.10.07-03.12.55:426][683]LogWindows:Error: Fatal error: [File:D:\Build\++UE4+Release-4.13+Compile\Sync\Engine\Source\Editor\UnrealEd\Private\EditorLevelUtils.cpp] [Line: 425] 
[2016.10.07-03.12.55:426][683]LogWindows:Error: World /Game/Maps/S_Hub_Industry.S_Hub_Industry didn't get garbage collected!
[2016.10.07-03.12.55:426][683]LogWindows:Error:    (Object is not currently rooted)
[2016.10.07-03.12.55:426][683]LogWindows:Error: 
[2016.10.07-03.12.55:426][683]LogWindows:Error: 
[2016.10.07-03.12.55:426][683]LogWindows:Error: 
[2016.10.07-03.12.55:426][683]LogWindows:Error: KERNELBASE.dll
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Core.dll!FOutputDeviceWindowsError::Serialize() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsplatformoutputdevices.cpp:103]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Core.dll!FOutputDevice::Logf__VA() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:94]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Core.dll!FDebug::AssertFailed() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:421]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-UnrealEd.dll!EditorLevelUtils::RemoveLevelFromWorld() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\editorlevelutils.cpp:425]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-WorldBrowser.dll!FLevelCollectionModel::UnloadLevels() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\worldbrowser\private\levelcollectionmodel.cpp:630]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-WorldBrowser.dll!FStreamingLevelCollectionModel::UnloadLevels() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\worldbrowser\private\streaminglevels\streaminglevelcollectionmodel.cpp:142]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-WorldBrowser.dll!TBaseSPMethodDelegateInstance<0,FStreamingLevelCollectionModel,0,TTypeWrapper<void> __cdecl(void)>::Execute() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:317]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-WorldBrowser.dll!TBaseSPMethodDelegateInstance<0,FStreamingLevelCollectionModel,0,void __cdecl(void)>::ExecuteIfSafe() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:423]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!FUICommandList::ExecuteAction() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\commands\uicommandlist.cpp:92]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!SMenuEntryBlock::OnClicked() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:1027]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!SMenuEntryBlock::OnMenuItemButtonClicked() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:987]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!TMemberFunctionCaller<SMenuEntryBlock,FReply (__cdecl SMenuEntryBlock::*)(void) __ptr64>::operator()<>() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstanceinterface.h:161]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter<TMemberFunctionCaller<SMenuEntryBlock,FReply (__cdecl SMenuEntryBlock::*)(void) __ptr64> >() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\tuple.h:115]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!TBaseSPMethodDelegateInstance<0,SMenuEntryBlock,0,FReply __cdecl(void)>::Execute() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:317]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!TBaseDelegate<FReply>::Execute() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:521]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!SButton::OnMouseButtonUp() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\widgets\input\sbutton.cpp:278]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!SMenuEntryButton::OnMouseButtonUp() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:385]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1>::operator()() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4901]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1> >() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:215]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!FSlateApplication::RoutePointerUpEvent() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4890]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!FSlateApplication::ProcessMouseButtonUpEvent() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5348]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Slate.dll!FSlateApplication::OnMouseUp() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5328]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Core.dll!FWindowsApplication::ProcessDeferredMessage() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1584]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Core.dll!FWindowsApplication::DeferMessage() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1930]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Core.dll!FWindowsApplication::ProcessMessage() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:747]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Core.dll!FWindowsApplication::AppWndProc() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:669]
[2016.10.07-03.12.55:426][683]LogWindows:Error: USER32.dll
[2016.10.07-03.12.55:426][683]LogWindows:Error: USER32.dll
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor-Core.dll!FWindowsPlatformMisc::PumpMessages() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:905]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor.exe!FEngineLoop::Tick() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2788]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor.exe!GuardedMain() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\launch.cpp:156]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor.exe!GuardedMainWrapper() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor.exe!WinMain() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:202]
[2016.10.07-03.12.55:426][683]LogWindows:Error: UE4Editor.exe!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
[2016.10.07-03.12.55:426][683]LogWindows:Error: KERNEL32.DLL
[2016.10.07-03.12.55:426][683]LogWindows:Error: ntdll.dll
[2016.10.07-03.12.55:426][683]LogWindows:Error: ntdll.dll
[2016.10.07-03.12.55:426][683]LogWindows:Error: 
[2016.10.07-03.12.55:451][683]LogExit: Executing StaticShutdownAfterError
[2016.10.07-03.12.55:486][683]LogWindows: FPlatformMisc::RequestExit(1)
[2016.10.07-03.12.55:486][683]Log file closed, 10/07/16 14:12:55