Unreal Engine Issues
Unreal Engine Issues
Changing the ComponentClass of a ACharacter twice and trying to set a SkeletalMeshAsset crashes the engine
UE - Runtime - Animation - Jan 22, 2026Changing the ComponentClass of a ACharacter twice and trying to set a SkeletalMeshAsset crashes the engine with a "Cannot replace existing object of a different class" message. The conditions to re ...
Assert crash when playing Groom Cache with Card Mesh LOD
UE - Rendering - Graphics Features - May 29, 2026Playing a Guides Groom Cache while Card Mesh LOD (Guide-Based) is active causes an assert in RunHairStrandsInterpolation_Cards when the renderer switches to Card LOD. Assert location:Plugins/Runtim ...
Crash due to D3D device being lost. (Error: 0x887A0006 - 'HUNG')
UE - Graphics Features - Feb 22, 2017This JIRA has been made to consolidate all "D3D device being lost. (Error: 0x887A0006 - 'HUNG')" crashes into one. Previous Jira tickets include:[Link Removed][Link Removed][Link Removed][Link Remo ...
[CrashReport] Access violation - FLandscapeEditDataInterface::SetAlphaData()
UE - LD & Modeling - Terrain - Landscape - Jul 19, 2017This is a common crash affecting users in 4.15 and 4.16. This callstack was previously linked to [Link Removed], but that had a specific repro case that was fixed in 4.14. Users are not providing ...
Loading a blueprint with an invalid gameplay tag container pin causes ensure and data loss
UE - Gameplay - Feb 23, 2021The gameplay tag system depends on tags being registered with the global manager as valid in order to correctly read them off disk. Two different issues are combining to cause a confusing ensure and ...
Chaos : Rigid body sleeps when very small external force is applied by AddForce
UE - Runtime - Simulation - May 25, 2022When a small external force is applied to the rigid body, the VSmooth value is reset in the ResetVSmoothFromForces function. Since this function ignores the current velocity, a very small velocity ...
Typo in GetAsBoundsArray() from file AABBTree.h on Chaos module
UE - Runtime - Simulation - Jul 30, 2025From file [Engine\Source\Runtime\Experimental\Chaos\Public\Chaos\AABBTree.h], function Chaos::TAABBTree<>::GetAsBoundsArray(): bool GetAsBoundsArray(TArray<TAABB<T, 3>>& AllBounds, int32 NodeIdx, i ...
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 ...
Widgets will bind input delegates to the Player Controller's Input Component, but never unbind them
UE - AI Workflows - UI Systems - UMG - Jan 30, 2024This is a bug introduced with 18468289 a while ago. We added this functionality for [Link Removed] Closed , which allows inp ...
Setting a struct bool property (bitfield) to itself writes the wrong value
UE - Framework - Blueprint Compiler - Sep 17, 2025There's an issue when assigning a bitfield bool to a native bool in Blueprints. Currently, the engine erroneously treats the memory for a local bool as a uint8 bitfield, which is undefined behavior. ...