How do I resolve/Understand this error

This happens when I hit a trigger, that makes a streaming level invisible, and another level visible. Could someone help me disect this, and understand how to handle these kinds of errors for future problems, and of course to handle this one besides deleting components one by one.

LogOutputDevice: === Handled error: ===
Ensure condition failed: false [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.9\Engine\Source\Runtime\Engine\Private\Components\SceneComponent.cpp] [Line: 1200]
Template Mismatch during attachment. Attaching instanced component to template component. Parent ‘CollisionCylinder’ Self ‘Arrow’
Stack:
UE4Editor-Core.dll!FWindowsPlatformStackWalk::StackWalkAndDump() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\private\windows\windowsplatformstackwalk.cpp:175]
UE4Editor-Core.dll!FDebug::EnsureFailed() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\private\misc\outputdevice.cpp:258]
UE4Editor-Core.dll!FDebug::OptionallyLogFormattedEnsureMessageReturningFalse() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\private\misc\outputdevice.cpp:368]
UE4Editor-Engine.dll!USceneComponent::AttachTo() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\components\scenecomponent.cpp:1200]
UE4Editor-Engine.dll!USceneComponent::OnRegister() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\components\scenecomponent.cpp:370]
UE4Editor-Engine.dll!UPrimitiveComponent::OnRegister() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\components\primitivecomponent.cpp:389]
UE4Editor-Engine.dll!UActorComponent::ExecuteRegisterEvents() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\components\actorcomponent.cpp:1040]
UE4Editor-Engine.dll!UActorComponent::RegisterComponentWithWorld() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\components\actorcomponent.cpp:825]
UE4Editor-Engine.dll!AActor::IncrementalRegisterComponents() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\actor.cpp:3656]
UE4Editor-Engine.dll!ULevel::IncrementalUpdateComponents() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\level.cpp:755]
UE4Editor-Engine.dll!UWorld::AddToWorld() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\world.cpp:1812]
UE4Editor-Engine.dll!UWorld::UpdateLevelStreamingInner() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\world.cpp:2418]
UE4Editor-Engine.dll!UWorld::UpdateLevelStreaming() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\world.cpp:2479]
UE4Editor-Engine.dll!UGameViewportClient::Draw() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\gameviewportclient.cpp:1027]
UE4Editor-Engine.dll!FViewport::Draw() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\unrealclient.cpp:1011]
UE4Editor-UnrealEd.dll!UEditorEngine::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\editor\unrealed\private\editorengine.cpp:1523]
UE4Editor-UnrealEd.dll!UUnrealEdEngine::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\editor\unrealed\private\unrealedengine.cpp:366]
UE4Editor.exe!FEngineLoop::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\launchengineloop.cpp:2428]
UE4Editor.exe!GuardedMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\launch.cpp:142]
UE4Editor.exe!GuardedMainWrapper() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor.exe!WinMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]
UE4Editor.exe!__tmainCRTStartup() [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]
KERNEL32.DLL
ntdll.dll
ntdll.dll
LogStreaming:Display: UWorld::AddToWorld: updating components for /Game/Ours/Levels/UEDPIE_0_SideCastleFirst took (less than) 18302.48 ms