Unreal Engine Issues

External Actors can hold stale references to Blueprint classes as edited instance properties

When a component is removed from a class that exists as an instance with external actors enabled, a deleted BP component on an actor will remain referenced by the instance. Disabling External Actor ...

Incorrect config property serialization for UStructs used as TMap keys or contained in a TSet with a single value. Diffs taken from default-value of each member type, instead of from default-value of the struct

Consider a UStruct with some basic type members, each one with a default value specified in the struct. Also consider a TSet or TMap with that struct as keys, used inside a UObject as a UProperty an ...

Crashing when toggling maps containing Color Correct Regions

When maps with Color Correct Regions are streamed into another map have their visibility toggled during runtime, it will cause a memory access violation and crash the editor. ...

Shadow Maps performance issue with 5.4 in comparison towards 5.3

Shadow depths performance for non-VSM in certain scenes, notably those with rect lights and meshes that are set to movable, went from ~2ms to ~18ms going from UE 5.3 to UE 5.4. Setting the movable a ...

Small UInstancedStaticMeshComponent::UpdateInstanceTransformById bug

The call to UpdateInstanceTransform within UInstancedStaticMeshComponent::UpdateInstanceTransformById(..) sends bTeleport in place of bMarkRenderStateDirty that was added as part of Unreal Engine 5. ...

StopMontage with different BlendOutTime not taken into account after first StopMontage

When an animation is currently blending out due to automatic blend out or GameplayLogic, further StopMontage with specific BlendOut will not update the time to blend out of the current blending out ...

Global SkyAtmosphere and Clouds Issues (Cloud Shadows)

Sampling Cloud Shadows when rendering the Sky Atmosphere can incorrectly assume that the view is located at the planet's North Pole. This causes distortion in the shadows when using a sphere-shaped ...

Global SkyAtmosphere and Clouds Issues (Ambient Light)

Ambient Light on Volumetric Clouds from Sky Atmosphere always is calculated as if the clouds are at the north pole of the planet. Using a sphere-shaped Sky Atmosphere and Volumetric Clouds causes t ...

Duplicated TextureLoadVirtualPageTable in GetCustomData functions in generated HLSL add to the total instruction count due to TextureLoad having side effects

When using materials with CustomData inputs, such as the Eye material with Iris Distance and Mask, Virtual Texture samples will increase the instruction count for each unique VTPageResult. Each cus ...

Playing a Haptic Soundwave will crash the editor