Crash in AWorldDataLayers::InitializeDataLayerRuntimeStates() when quickly unloading then loading a sub-world partition

UE - World Creation - Worldbuilding Tools - Data Layers - Mar 6, 2025

From licensee: Since we integrated 5.5, we are experiencing a crash in AWorldDataLayers::InitializeDataLayerRuntimeStates() on this line check(ActiveDataLayerNames.IsEmpty() && LoadedDataLayerN ...

Custom Depth range is different than Pixel Depth range

UE - Graphics Features - Sep 25, 2025

Shaders that compare custom depth and pixel depth get wrong output values because the ranges are different. This error is most noticeable over large distances. The difference in ranges is due to t ...

When r.SSR.Stencil is enabled, there is wrong logic observed.

UE - Graphics Features - Dec 19, 2025

When r.SSR.Stencil is enabled, the areas with high roughnesss are not discarded and Unlit materials are incorrectly handled. See the linked EPS case (Additional Info URL) for a full explanation of ...

Compile failure launching C++ project onto tvOS/iOS in Development

UE - Platform - Mobile - Apr 13, 2017

This is the same issue as UE-41313 but is showing up in the release branch.[2017.04.12-21.37.50:215][354]LogPlayLevel: UnrealBuildTool: /Users/Shared/UnrealEngine/4.16/Engine/Source/Runtime/Core/Pub ...

[CrashReport] UE4Editor_UMG!TBaseDelegate<FMargin>::operator=() [delegatesignatureimpl.inl:381]

UE - Editor - UI Systems - Aug 29, 2017

This is a longstanding and common UMG crash that has affected more than 200 users since at least the 4.15 release. User DescriptionsI was working in the UI and undid several last changes in quick s ...

[CrashReport] UE4Editor_UnrealEd!FBlueprintCompileReinstancer::ReplaceInstancesOfClass_Inner() [kismetreinstanceutilities.cpp:1880]

UE - Gameplay - Blueprint Compiler - Oct 5, 2017

This is a somewhat common crash that has occurred throughout the 4.17 release. Users have not provided any description of their actions when the crash occurred. The callstack is similar to some ol ...

Always Relevant actor may replicate incorrect movement mode when the walkable floor becomes irrelevant

UE - Gameplay - Player Movement - Feb 26, 2024

When the character class is set to always relevant, if a client travels very far away from another character, such that the character is relevant but the component they're standing on is not (but al ...

PakFiles: Unmounting PakFile while requests are still in progress causes assertion failure in UnMount

UE - Foundation - Mar 31, 2022

[Link Removed] Licensee is using the chunk downloader. On Shutdown method of their GameInstance, they call FChunkDownloader->Finalize. When they quit the game (Alt+F4) during a chunck download an a ...

[CrashReport] UE4Editor_Engine!UHierarchicalInstancedStaticMeshComponent::BuildTreeIfOutdated

UE - World Creation - Worldbuilding Tools - Foliage - Jun 8, 2017

This is a common crash occurring in the 4.16 release. It seems to be related to applying a material to a mesh that is being used in Foliage. Crash Reports are spread out among many different Crash ...

Slowly flickering display in GearVR

UE - Platform - XR - Jul 12, 2017

The appears repeatedly in the log:[2017.07.12-14.57.06:022][ 4]LogHMD: Initializing OVRPlugin session [2017.07.12-14.57.06:652][ 4]LogHMD: Setting user focus to game viewport since session status ...