Unreal Engine Issues
Unreal Engine Issues
[AI] Destroying an actor while using pooled actors with MassActorSpawnerSubsystem causes a nullptr exception crash
UE - AI - Mass - Mar 19, 2023If an actor that is used in the pooled actor list of UMassActorSpawnerSubsystem is destroyed, it causes a nullptr exception in UMassActorSpawnerSubsystem::SpawnOrRetrieveFromPool. The subsystem atte ...
NavMesh does not build correctly to SkeletalMesh collision
UE - AI - Mar 16, 2015NevMesh cuts out holes for collision incorrectly with Skeletal Meshes. Skeletal Meshes with "Can Ever Affect Navigation" set to true and that have a Physics Asset are capable of causing this. ...
Calling a blueprint function library within a blueprint prevents blueprint from being saved
UE - Gameplay - Blueprint - Mar 25, 2015Blueprint cannot save when a function from a function library is present in the blueprint unless any alteration is made within the function library. Once editor is closed and re-opened the user must ...
[Groom] Very thin hair has incorrect raytraced shadow on edges
UE - Graphics Features - Lumen - Jun 8, 2020This only happens when 1) Hair Width is very small. e.g. 0.01 in the example 2) Light has raytraced shadow and Samples Per Pixel has a value > 1. e.g. 8 in the example The problem seems to be rel ...
Actors in Level Sequence in a World Partitioned level do not move
UE - World Creation - Worldbuilding Tools - World Partition - Jan 11, 2023Regression: Tested in UE5/Release-5.0, this issue does not occur so it is a regression This issue occurs when the cube has "Is Spatially Loaded" enabled in Details as well as when the cube is added ...
Static lights become stationary after toggling visiblity of level in packaged build
UE - Graphics Features - Jun 11, 2025In 5.5, there is a regression with baked lighting where static lights become stationary lights when a level is hidden and then made visible again. This happens in packaged builds and shows up as sta ...
Streaming Virtual Texture UDIN V Offsetting
UE - Editor - Content Pipeline - Import and Export - Jan 31, 2024UDIN virtual textures appear to have row 0 (U coordinate [0 - 1) swapped to the other side of the texture vertically. ...
Editor crashes when opening several marketplace assets - Assertion failed: !HasAnyFlags
UE - Gameplay - Blueprint - Jun 22, 2016Editor crashes while attempting to open several marketplace assets. Allar's Generic Shooter Defuse Studios RTS Template JCInventory Frequency: 5/5 Regression (yes) issue (does not) occur in 4.11 ...
Local Variable loses value after reference moves file location
UE - Gameplay - Blueprint - May 23, 2017Local Variable loses value after reference moves file locations. This does not just affect construction scripts, following these steps with a function instead produced the same result. This issue do ...
FHLSLMaterialTranslator::GetMaterialEnvironment can crash or not load UMaterialParameterCollections
UE - Rendering Architecture - Materials - Apr 30, 2025In UE 5.5, the Editor may crash in FHLSLMaterialTranslator::GetMaterialEnvironment when loading materials with Material Parameter Collections, likely due to async loading. Calling ParameterCollectio ...