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 ...

Painted Foliage Instances Randomly Culling in Splitscreen Multiplayer

UE - World Creation - Worldbuilding Tools - Foliage - Mar 15, 2017

Foliage instances are behaving strangely when playing splitscreen multiplayer in a single instance window. The instances will cull in and out of visibility depending on the size of the current playa ...

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 ...

The packaged build of a project that has a strong pointer initialized to nullptr immediately closes on launch

UE - Foundation - Core - Aug 2, 2019

When a strong pointer is set to null the packaged build of the game will immediately close. No crash logs were were made and no Saved folder was made (<Project Name>/Saved/Logs). An example project ...

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 ...