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 ...

Crash when Dragging Skeletal Mesh with Apex Clothing into Level

UE - Simulation - Physics - Character - Nov 29, 2016

A crash occurs when you add/drag a skeletal mesh with Apex clothing into the scene. The user reporting the issue managed to find where the crash occurs and added a comment for assistance where to lo ...

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 ...

Sequencer does not save asset variables in event struct

UE - Anim - Sequencer - Jul 31, 2018

When adding a struct to a keyframe, Object Reference variables are not saved and Soft Reference variables are saved sometimes. Opening a keyframe's properties when the selected struct has an object ...

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 ...

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 ...

Incorrect volume bounds check in FTranslucentLightInjectionCollector::AddLightForInjection

UE - Graphics Features - Apr 8, 2025

The 'VolumeBounds' array in FTranslucentLightInjectionCollector::AddLightForInjection is accessed as a pointer instead of with 'VolumeCascadeIndex' and thus fails bounds checks for the outer volume. ...

Lighting Scenarios Map Check warning about multiple skylights not supported

UE - Graphics Features - Dec 5, 2016

When using Lighting Scenarios and placing a skylight in the lighting scenario levels when you build lighting there will be a map check warning that "Multiple sky lights are active, only one can be e ...