I sometimes get following crash while using a tiled landscape in ue 4.26
Assertion failed: Pair != nullptr [File:D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Public\Containers/Map.h] [Line: 621]
UE4Editor_Core!AssertFailedImplV() [D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Private\Misc\AssertionMacros.cpp:102]
UE4Editor_Core!FDebug::CheckVerifyFailedImpl() [D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Private\Misc\AssertionMacros.cpp:458]
UE4Editor_Landscape!FLandscapeNeighborInfo::RegisterNeighbors() [D:\Build++UE4\Sync\Engine\Source\Runtime\Landscape\Private\LandscapeRender.cpp:4498]
UE4Editor_Renderer!FScene::OnLevelAddedToWorld_RenderThread() [D:\Build++UE4\Sync\Engine\Source\Runtime\Renderer\Private\RendererScene.cpp:3620]
UE4Editor_Renderer!TEnqueueUniqueRenderCommandType<FScene::OnLevelAddedToWorld'::
2’::FLevelAddedToWorldName,<lambda_5efb62cc65a4fc08e132722ed967a4f6> >::DoTask() [D:\Build++UE4\Sync\Engine\Source\Runtime\RenderCore\Public\RenderingThread.h:183]
UE4Editor_Renderer!TGraphTask<TEnqueueUniqueRenderCommandType<FScene::OnLevelAddedToWorld'::
2’::FLevelAddedToWorldName,<lambda_5efb62cc65a4fc08e132722ed967a4f6> > >::ExecuteTask() [D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Public\Async\TaskGraphInterfaces.h:886]
UE4Editor_Core!FNamedTaskThread::ProcessTasksNamedThread() [D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Private\Async\TaskGraph.cpp:709]
UE4Editor_Core!FNamedTaskThread::ProcessTasksUntilQuit() [D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Private\Async\TaskGraph.cpp:601]
UE4Editor_RenderCore!RenderingThreadMain() [D:\Build++UE4\Sync\Engine\Source\Runtime\RenderCore\Private\RenderingThread.cpp:373]
UE4Editor_RenderCore!FRenderingThread::Run() [D:\Build++UE4\Sync\Engine\Source\Runtime\RenderCore\Private\RenderingThread.cpp:509]
UE4Editor_Core!FRunnableThreadWin::Run() [D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Private\Windows\WindowsRunnableThread.cpp:86]
How can I see what is causing this crash?