GPU Lightmass no longer works with cascaded shadow maps

UE - Graphics Features - May 29, 2025

Since Unreal Engine 5.5 stationary lights have stopped working with GPU Lightmass when using Cascaded Shadow Maps. With Virtual Shadow Maps enabled on the project, GPU Lightmass works. This issue d ...

Light Mixer - All of the Light Attributes disappear when you have Show Only Selected enabled

UE - Virtual Production - Tools - Jun 13, 2025

All of the Light Attributes disappear when you have Show Only Selected enabled. ...

Crash in FUniformExpressionSet::FillUniformBuffer trying access deleted UTextureCollection

UE - Rendering Architecture - May 30, 2025

Crash in FUniformExpressionSet::FillUniformBuffer trying access deleted UTextureCollection (Experimental in 5.6). The licensee describes their crash, their analysis, and a proposed fix: This crash ...

Runing PlayInEditor with NetMode PlayAsClient and a LevelSequence that AutoPlays in the level and is also opened in Sequencer leads to a Fatal world leak crash on 5.5 and up

UE - Anim - Sequencer - May 28, 2025

Runing PlayInEditor with NetMode PlayAsClient, a LevelSequence that AutoPlays in the level, contains a Spawnable BP_ThirdPersonCharacter with an animation, and is also opened in Sequencer, leads to ...

Niagara Regression - Looping particle with Spawn Burst Instantaneous on time 0.0 flickers for a frame between loops

UE - Niagara - Jul 16, 2025

Note: This worked correctly up to UE 5.4, but repros from UE 5.5 up to mainline latest. If a Niagara Emitter is set up with "Spawn Burst Instantaneous" on time 0.0, and the spawned particle(s) have ...

Saving Behavior Tree with Blueprint task inheriting from native class invalidates Blackboard key when BP contains a function

UE - AI - Jul 8, 2025

A regression introduced in UE 5.6 causes Blackboard key selectors in Blueprint tasks to become invalid when the Blueprint inherits from a native subclass of UBTTask_MoveTo (or UBTTask_BlackboardBase ...

Editor will crash when Blueprint Details Panel is dragged across the Event Graph

Tools - May 6, 2015

When dragging the Details Panel in a Blueprint across the event graph the editor will crash. [Link Removed] ...

Crash when setting console command for shadow max resolution to 1

UE - Graphics Features - May 29, 2015

When setting the console command r.shadow.MaxResolution to a value of 1 will cause a crash. CrashReporter: [Link Removed] ...

Visible dithered quantization to remove banding in New Temporal AA Quality

UE - Graphics Features - Oct 6, 2015

Since changing the temporal history buffer to 11:11:10 from FP16, it looks as there is visible dithered quantization to remove banding when rendering. (Taken from conversation on Forum Post linked f ...

VC Runtime not in UnrealLightmass temp directory; causing lightmass build errors

UE - Foundation - Cpp Tools - UnrealBuildTool - Oct 14, 2015

A Redistribute file for VS 2015 is needed to build lightmass, but this is not currently included with the engine. If a user does not have VS 2015 installed, lightmass will fail with this error: Un ...