Unreal Engine Issues
Unreal Engine Issues
RigVMRegistry : The registry is not locked for writing yet : ensure statement error during cook
UE - Anim - Rigging - Control Rig - Sep 2, 2025I am seeing an cook failure at the very beginning. It goes away with a retry step via Horde. Please find attached call stack. I am able to consistently reproduce it by wiping all the DDC cache and ...
Negatively scaled box collisions render back faces in Player Collision debug view
UE - Simulation - Physics - Sep 1, 2025The player collision debug visualization for negatively scaled boxes is rendering the back faces, not the front faces. The debug primitives are rendered via the dynamic mesh builder. FDynamicMeshBui ...
Hardware Lumen Surface Cache Artifacts on Nanite Geometry
UE - Graphics Features - Lumen - Sep 1, 2025When using Hardware Lumen with Nanite-enabled meshes in UE 5.6+, black / dark surface cache artifacts appear that result in generally darker and unstable lighting. These artifacts are not immediatel ...
Material Particle SubUV Sample does not work with Tex Object
UE - Rendering Architecture - Materials - Aug 29, 2025The Particle SubUV Sample node uses its own texture object reference instead of the one provided by the texture object node. ...
Crash When Loading Cooked Material Assets in Editor Due to Shader Serialization
UE - Rendering Architecture - Shaders - Aug 27, 2025In Unreal Engine 5.6+, the new shader serialization logic in FShaderMapResourceCode::Serialize does not correctly handle cooked assets that are loaded back into the editor (e.g., from a mounted .pak ...
GAS: Double attributes not shown GameplayDebugger
UE - Gameplay - Gameplay Ability System - Aug 27, 2025Context The Gameplay Ability System lets devs specify numerical attribute properties in UAttributeSet subclasses. Although the preferred attribute property type is FGameplayAttributeData, GAS has l ...
StateTree : Crash when executing GetPropertyRef in SubTree linked via Linked Asset
UE - AI - StateTree - Aug 26, 2025A crash occurs when GetPropertyRef node is executed from a SubTree that is linked within a StateTree, which itself has been linked from a parent StateTree via a Linked Asset ** . The processing con ...
BP Debugger: Unable to inspect debug data for ForEachLoop ArrayElement, Array_Get and Break Struct output pins
UE - Framework - Blueprint - Aug 26, 2025Context The blueprint debugger allows you to trigger breakpoints and inspect the current state of variables, both member variables, local variables and persistent UberGraph variables. Problem The ...
Heterogeneous Volume Actor causes ensures to trigger in Debug builds
UE - Niagara - Aug 24, 2025When a heterogeneous volume actor is used with a volume material in a debug build, the following ensures are triggered: Ensure condition failed: UniformBufferValue || EnumHasAnyFlags(AutomaticallyBo ...
Adding pin to CR node causes crash if input variable is assigned to one of the array element
UE - Anim - Rigging - Control Rig - Aug 22, 2025When a node has a variable assigned to one of its pins. You will get a crash every time you add a pin. I am sure this goes for all nodes with with the "add pin" functionality [Link Removed] ...