Unreal Engine Issues
Unreal Engine Issues
Interchange GLTF importer truncates skeletal mesh bone influences to 4 per vertex
UE - Editor - Open File Formats - Aug 21, 2026cf https://forums.unrealengine.com/t/interchange-gltf-importer-truncates-skeletal-mesh-bone-influences-to-4-per-vertex/2745391/2 Original message The UE5 Interchange GLTF importer appears to trunc ...
FGameplayTagCountContainer::Reset() leaves explicit tag state and causes counts to accumulate
UE - Gameplay - Gameplay Tags - Aug 4, 2026[Summary] In UE 5.7 and later, if a tag is added once to an FGameplayTagCountContainer, the container is reset, and the same tag is added once more, GetExplicitTagCount() returns 2 instead of the e ...
FAssetFixUpRedirectors::FixupReferencers cannot be run silently
UE - Editor - Aug 3, 2026SFixupRedirectorsReport was added with 31698013. There is no way to prevent the UI from showing so the code cannot be used in unattended mode. ...
[CrashReport][Crash] Engine!FSceneViewport::UpdateViewportRHI() [SceneViewport.cpp]
UE - Rendering - RHI - May 29, 2026#200 crash out of 2101 in UE 5.8 on Windows#34 crash for UE - Rendering - Architecture in UE 5.8 on Windows#20 crash for UE - Rendering - Architecture - RHI in UE 5.8 on WindowsAssertion failed: IsI ...
Open Formats: Interchange Import - UCX Convex Hull Import Bug
UE - Editor - Open File Formats - May 25, 2026When importing custom UCX collision meshes from FBX files into Unreal Engine, certain geometry profiles fail to generate correctly if the option "One Convex Hull Per UCX" is unchecked. The engine's ...
UAbilityTask_SpawnActor::BeginSpawningActor may return true when SpawnedActor contains stale value
UE - Gameplay - Gameplay Ability System - Mar 15, 2026UAbilityTask_SpawnActor::BeginSpawningActor assumes the incoming AActor*& SpawnedActor parameter is nullptr if no actor was spawned, but it does not initialize the parameter at the start of the func ...
Cluster Group Index Causes Incorrect Break Events in Geometry Collections
UE - Runtime - Deformable - Feb 25, 2026More details in this [Link Removed] ...
Incorrect geometry for OnMouseMove event on Slider with RightToLeft flow direction
UE - AI Workflows - UI Systems - Slate - Jan 28, 2026When a slider is in RTL flow direction, and thus its position is changed, the handle is not drawn at the correct position during mouse drag. Instead, the handle draws as if the slider was not moved ...
Controller Mapping/Unmapping on some platforms is not ideal for local multiplayer
UE - Gameplay - Input - Nov 19, 2025[Link Removed] The workaround is as I posted in the UDN, to override the viewport client or to make a custom slate input mapping to change this behavior. But, there is a bug with that unmapping/l ...
ChordBlockers don't work as expected when ChordAction is set in InputAction
UE - Gameplay - Input - Jun 3, 2025In the Enhanced Input System, when using a UInputTriggerChordAction to define a chorded input (e.g., Shift + W), the automatic chord blocking system (UInputTriggerChordBlocker) only functions correc ...