Unreal Engine Issues
Unreal Engine Issues
Enabling Override Instance Data to a LevelSequencerActor that has a Shot Track can lead to crashing the engine
UE - Anim - Sequencer - Mar 17, 2025Enabling Override Instance Data to a LevelSequencerActor that has a Shot Track can lead to an Actor being translated really far, or even a crash in the engine. The licensee has encountered a particu ...
Niagara color picker user parameter preview no longer updates until confirmation
UE - Niagara - Apr 18, 2025Starting with UE 5.4, the Color Picker Tool no longer updates preview values in real time for certain editor windows like Niagara when working with User Parameters. This behavior is a regression fr ...
GPU Lightmass no longer works with cascaded shadow maps
UE - Graphics Features - May 29, 2025Since 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, 2025All 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, 2025Crash 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, 2025Runing 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, 2025Note: 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, 2025A 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 ...
Crashes after destroying a skeletal mesh attached via socket name (not bone name), the destroyed mesh remains welded.
UE - Simulation - Core - Jul 18, 2025On welding physics bodies during primitive component attachment, UPrimitiveComponent::WeldToImplementation() calls GetRootWelded() and then GetBodyInstance() on the returned root. This searches by b ...
Geometry Collection cluster handles leaking and causing ensures with field systems
UE - Simulation - Visual - Aug 26, 2025Geometry Collection cluster handles leaking and causing ensures with field systems. The licensee has shared their analysis: We have been tracking down an assert that seems to happen occasionally wh ...