Editor becomes unresponsive for long periods between edits of a user-defined enum type when it's referenced by one or more user-defined struct types.

UE - Gameplay - Blueprint - May 17, 2021

After adding a member to a user-defined struct type and changing the member type to a user-defined enumeration, repeated edits to that enumeration will eventually cause the editor to become increasi ...

VolumetricLightmap doesn't work when shifting a level by world origin rebasing

UE - Graphics Features - May 17, 2021

VLM is not handled when rebasing. The following workaround works. void SetupPrecomputedVolumetricLightmapUniformBufferParameters(const FScene* Scene, FEngineShowFlags EngineShowFlags, FViewUniform ...

InstancedStaticMesh displaying corrupt lightmap data

UE - Graphics Features - May 17, 2021

I think I narrowed this issue down to bad UV coordinates being interpreted during the BasePassVertexShader execution applied to instancing. At this line in VertexFactoryGetInterpolantsVSToPS: flo ...

Sorting objects at EndLoad has a non-deterministic behavior

UE - Foundation - Core - EditorLoader - May 14, 2021

This non-deterministic behavior is caused by sorting by program address. ...

SkeletalMesh may lose virtual bone names

UE - Editor - Content Pipeline - Asset Build - May 14, 2021

This Jira is there to make sure we load the skeleton asset before the skeletalmesh asset need it ...

[Submix][Content Browser] - Deleting an unsaved Submix asset (any type) causes them to reappear when creating a new asset

UE - Audio - Submixes - May 13, 2021

Deleting unsaved Submix assets causes them to reappear the next time you create a new asset. Issue does not occur in 4.26, but does occur in 4.27 and 5.0. ...

Crash on multi viewport when streaming in sub level with rect lights

UE - Rendering Architecture - RHI - May 13, 2021

Very thin meshes cause flickering with emissive materials.

UE - Graphics Features - May 13, 2021

The licensee has reported that when you make a mesh extremely thin (e.g. z = 0.0001), it can cause emissive materials applied to the mesh to flicker. ...

Crash when adding an Event Write node to a Niagara Scratch Pad module

UE - Niagara - May 13, 2021

It seems that the crash is related to all of the "Write" events. I tested the Event ChaosDestruction Write, Event Float Write, and Event Bool Write and all 3 caused the crash, but their "Read" count ...