Unreal Engine Issues
Unreal Engine Issues
Cook Non-Determinism in USplineComponent
1. Non-Deterministic LastAuthority Serialization LastAuthority is assigned in USplineComponent::Serialize. Its value depends on the order in which the object and its archetype are serialized, leadi ...
Crash caused by a race condition in Nanite::DispatchBasePass()
Nanite::BuildShadingCommands() launches two asynchronous tasks: ShadingCommands.SetupTask ShadingCommands.BuildCommandsTask BuildCommandsTask is responsible for modifying ShadingCommands.Commands ...
Visual discrepancy between lighting in Cloud Presenter and editor viewport
TM - Rendering - Feb 24, 2026Reported in SF [Link Removed] In this user’s scene, the lighting in the Cloud Presenter does not match the lighting in the editor viewport. The Cloud scene is notably darker than the editor. The s ...
Motion Matching FPS instability causes jittering when using the root offset node
UE - Anim - Gameplay - Feb 23, 2026Offset root node is affected by frame rate and produces jitter in it's motion across various settings and styles. ...
Occlusion Queries for Static Meshes with ERuntimeVirtualTextureMainPassType::Exclusive
UE - Rendering - Architecture - Feb 20, 2026Static Meshes that draw into RVTs and have "Draw In Main Pass" is set to "From Virtual Texture" (ERuntimeVirtualTextureMainPassType::Exclusive) will still draw in Occlusion Queries. This can be tr ...
Unstable automation tests in "Standard Tests" list.
UE - Rendering - Architecture - Feb 20, 2026The two following automation tests found in the "Standard Tests" list hit exceptions & cause the editor to crash:System->Physics->Interface->BodyInstanceShaders->ShaderPreprocessor->BuiltInMacros ...
anim notify states are triggered when updating thumbnails
UE - Anim - Runtime - Feb 19, 2026The issue is that FAnimationSequenceThumbnailScene::SetAnimation calls referesh bone transforms which will trigger notify states present at the midpoint of the animation (as the thumbnail code sets ...
Precaching global shaders with r.PSOPrecache.GlobalShaders = 2 crashes on startup
UE - Rendering - Architecture - RHI - Feb 19, 2026A licensee has reported that they are trying to run a cooked project with r.PSOPrecache.GlobalShaders=2 and running into a crash. They believe the problem is in PrecacheComputePipelineStatesForGlob ...
BP Event Dispatchers: Hidden reference from actor A -> B, if B bound to A's event dispatcher editor-time, unbound later, but actor A wasn't resaved.
UE - Framework - Blueprint Editor - Feb 19, 2026Context In blueprint, one can bind to a referenced actor’s events by clicking an actor reference variable, and creating an event node through the variable’s detail panel. Under the hood, this adds ...
Cloth - Assertion failed: SimData->LODIndex != INDEX_NONE && SimData->LODIndex <= LOD when using the rewind debugger with multiple LODs cloth
UE - Simulation - Visual - Feb 19, 2026The LOD switching when the simulation is paused could still be causing problems when the simulation is paused while the LOD indexes are going up because there is no LOD Bias mappings by default. Se ...