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 ...

Light leak on mesh when in shadowed area

UE - Graphics Features - Nov 8, 2017

When Cast Shadow and Self Shadow Only in the Lighting Section of the Details of a mesh, the light will randomly hit the mesh even though it is in a shaded area. Light appears to flicker and will com ...

First four landscape tools are not accessible in VR Editor Mode

UE - Editor - Workflow Systems - Jan 8, 2018

Tested in Oculus.  Found in 4.18.2 CL 3794801, 4.17.2 CL 3658906.  Not able to reproduce in 4.19 Main due to a crash upon launching VR Mode.   Users are able to select any of the first four sculpt ...

Foliage Not Updating to Match New Landscape Height After Level Save-As

UE - World Creation - Worldbuilding Tools - Foliage - May 3, 2018

I have observed this behavior in 4.18.3, 4.19.2, and Main (CL 4048405) Per User: I made a landscape, painted some foliage and saved the scene. After I saved the same scene under different name the ...

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 ...

Renaming a BP interface function/event breaks all existing uses of that function/event

UE - Gameplay - May 24, 2018

If you rename a blueprint interface function or event that is used somewhere in a blueprint, it will break the usage of that function/event. If it was a function, it will actually delete all the BP ...

AIController can't properly unpossess character

UE - AI - Nov 5, 2018

There seems to be a bug with the Possess\Unpossess events. Because if you change the last node in "PossessCharacter", which is created in PlayerController(called "PC"), to Unpossess the AI still con ...

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. ...