Unreal Engine Issues
Unreal Engine Issues
USkeletalMeshComponent::HandleExistingParallelClothSimulation() calling WaitUntilTaskCompletes can trigger arbitrary task that modifies currently iterated UWorld::ComponentsThatNeedPreEndOfFrameSync
UE - Rendering - Architecture - Feb 23, 2024Context ActorComponents can schedule an end-of-frame update for themselves by calling UWorld::MarkActorComponentForNeededEndOfFrameUpdate. The UWorld will iterate all those actor components once pe ...
“None” option removed from “Preview Game Language” in Editor Preferences since UE 5.6
UE - Editor - UI Systems - Oct 24, 2025In Unreal Engine 5.5 and earlier, users could select “None” as the Preview Game Language in the Editor Preferences. Starting from UE 5.6, this “None” option is no longer available. Based on source ...
FMovieSceneSkeletalAnimationParams::MapTimeToAnimation returns the wrong value if InFrameRate is not the Tick Resolution
UE - Anim - Sequencer - Jan 16, 2026FMovieSceneSkeletalAnimationParams::MapTimeToAnimation takes in an FFrameTime and FFrameRate and is supposed to tell you which frame of animation that evaluates to, when accounting for looping, play ...
Subsurface Profile material does not render properly in the Material Editor or Material Instance Editor
UE - Graphics Features - Dec 15, 2016Note: I looked for a similar or related bug but could not find one. Sorry if it's here and buried. Subsurface Profile materials render differently in the Material Editor Preview pane than they do a ...
[CrashReport] Mac crash in FThreadStats::FThreadStats()
UE - Platform - Apple - Jan 3, 2017This is a commonly reported crash from Mac users in the community. The repro steps are currently unknown, and appear to be varied based on user information below.zoomed out quickly while in a bluepr ...
Cannot hide most Blueprint categories from the Class Settings
UE - Gameplay - Blueprint - Apr 29, 2015Cannot hide most Blueprint categories from the Class Settings of a bp. x = Cannot hide Actor - Hid-able Add Component - x Add Event - x AI - x Animation - Hid-able Audio - Hid-able Canvas Render T ...
ApplyLocalExposure uses Output_ExtentInverse instead of Output_ViewportSizeInverse for bilateral grid UV
UE - Rendering - Graphics Features - May 18, 2026The ApplyLocalExposureCS shader in PostProcessLocalExposure.usf computes UV coordinates for the LumBilateralGrid 3D texture using Output_ExtentInverse (1/RenderTargetSize) instead of Output_Viewport ...
[CrashReport] UE4Editor_CoreUObject!FCompressedChunk::FCompressedChunk()
UE - Foundation - Core - Jul 24, 2017This is a common crash affecting users in 4.16 and the 4.17 Previews. The two descriptions provided by users say their crash occurred after updating their project from 4.13. User DescriptionsUpgra ...
Cached State Machine is re-initialized whenever cached pose is referenced
OLD - Anim - May 19, 2015This may not be an expected use of state machines, but it is becoming a showstopper for a couple of users. These user's are caching their locomotion state machine and then using a second state mach ...
AssetRegistry has poor performance when a large map is resaved
UE - CoreTech - Jun 21, 2024A licensee reports that their large map has a 10s cost in the AssetRegistry when resaved. They took a profile and found the cost is mostly in LoadCalculatedDependencies for the map, and most of that ...