Unreal Engine Issues
Unreal Engine Issues
Crash caused by Buffer Overread in TBitArray operator < function
UE - Foundation - Core - Aug 29, 2018A licensee has reported a crash that is caused by a Buffer Overread in TBitArray's operator < function. While the licensee did not provide reproduction steps, the crash is apparent from looking at t ...
Crash on loading pre-4.20 cloth data when compute skin cache is enabled in 4.21
UE - Graphics Features - Mar 19, 2019According to information from the licensee, the else clause was added to "FSkeletalMeshLODModel::(GetClothMappingData()" at CL 4437969 , but if it is the cloth data existing from 4.20 or earlier, it ...
UAIPerceptionSystem::Tick() has a chance of not being called after level reloading
UE - AI - Dec 16, 2019UAIPerceptionSystem::Tick() is not called after level reloading. When Debugging, UAIPerceptionSystem::CurrentTime is always 0, and UAIPerceptionSystem::SourcesToRegister always contains sources to ...
Compile on load crashes for classes within an abstract class
UE - Gameplay - Blueprint Compiler - Feb 20, 2021When compiling on load in -game, a blueprint class that inherits from a native class that is marked within and the class that it is within is abstract, a crash will occur when FBlueprintCompilationM ...
LOD dithered fade-out transition does not work since UE5.4
UE - Rendering Architecture - Aug 7, 2024When DitheredLODTransition is enabled for HierarchicalInstancedStaticMesh, in the previous version (5.1.1), dithering was applied during fade-in/fade-out, but in 5.4.3, dithering is not applied duri ...
Setting Slate.ShowBatching to 1 makes the entire screen green unexpectedly
UE - Editor - UI Systems - Slate - Jun 19, 2025This issue may have occurred due to a refactoring of the related functionality during the engine update from version 5.4 to 5.5. The main reason is that the randomization of BatchColor doesn't work ...
Path Tracer Normals Issue
UE - Graphics Features - Path Tracer - Oct 29, 2025Path Tracing normal maps reflect light differently than Lit, and do not look accurate. Also observed in //UE/Release-5.6, CL: 45232827 ...
Crash Occurs When Actors are Attached Across Persistent and Sublevels When Levels are Saved
UE - Anim - Sequencer - Dec 12, 2017Can attach actors to each other through the use of sequencer even though actors are in different levels which leads to crashing when saving and changing levels F3DAttachTrackEditor::IsActorPickabl ...
FBX Transform does not scale skeletal mesh with multiple pieces properly using the Import Uniform Scale option
UE - Editor - Content Pipeline - Import and Export - Aug 15, 2016Importing a skeletal mesh fbx from blender and setting the Import Uniform Scale option for the mesh to a higher value, like 100, results in only one of the meshes being scaled while the other is lef ...
Certain combined Linear/Angular movements cause Client to freeze for several seconds
UE - Simulation - Physics - May 24, 2019When using Replicated Movement, certain combined linear/angular movements cause the client to freeze for several seconds and then catch up to the server. This is a regression from 4.21.2 (CL-4753647 ...