Assertion opening blueprint with HISMC created in 4.11

UE - World Creation - Worldbuilding Tools - Foliage - Jun 7, 2016

After project was upgraded to 4.12 opening a blueprint that contains Hierarchical Instanced Static Mesh component will result in a crash. From the log I this is the important part: Assertion faile ...

Value of Mass In Kg is multiplying in value when clicked

UE - Simulation - Physics - Jul 27, 2017

When changing the value of Mass In Kg for a child of a Skeletal Mesh Actor, the value is getting multiplied with every select, deselect, and enter press on the value. The number the value is multipl ...

TPropertyValueIterator skips TMap values when KeyType is a UStruct

UE - Foundation - Core - May 7, 2018

From https://udn.unrealengine.com/questions/431271/tpropertyvalueiterator-skips-tmap-values-when-keyt.html The property value iterator has logic where it tries to iterate over all properties in a s ...

Crash caused by Buffer Overread in TBitArray operator < function

UE - Foundation - Core - Aug 29, 2018

A 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, 2019

According 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, 2019

UAIPerceptionSystem::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, 2021

When 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, 2024

When 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 ...

Crash Occurs When Actors are Attached Across Persistent and Sublevels When Levels are Saved

UE - Anim - Sequencer - Dec 12, 2017

Can 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, 2016

Importing 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 ...