Unreal Engine Issues
Unreal Engine Issues
SplineMeshComponent resources leak
UE - Rendering - Features - Aug 3, 2026A race condition occurs in the InitSplineVertexFactory_Internal }}function call, which is distributed across multiple threads. This causes {{FSplineMeshVertexFactory to be instantiated multiple time ...
Changes to Instanced Properties default value on BP not propagated to placed actors in the opened level
UE - Core - Systems - May 15, 2025In UE versions 5.4 and onwards (as of CL 42589677 in Main), when an Instanced UObject property is defined in an Actor Blueprint, modifying the default value in the Blueprint does not propagate the c ...
No arm64 folder exists in plugins leading to an Error when packaging plugins
UE - Core - Systems - Nov 16, 2022Regression: Checked in UE5/Release-5.0, the folder is missing from the plugin as well. This issue appears to be a problem with packaging the plugin itself, rather than packaging a full project. Pac ...
[CrashReport][GPUCrash] UpdateRadianceCaches
UE - Rendering - Features - Ray Tracing - May 19, 2025#31 crash out of 7783 in UE 5.7.4 on Windows#3 crash for UE - Rendering - Graphics Features in UE 5.7.4 on Windows#1 crash for UE - Rendering - Graphics Features - Ray Tracing in UE 5.7.4 on Windows ...
Nanite Displacement Bounds Mismatch Causes Floating Terrain Artifacts on Landscape
UE - Rendering - Features - Nanite - Mar 19, 2026Summary When Nanite Tessellation (Nanite Displacement) is enabled on a Landscape in UE 5.7.3, scaling the Displacement value via Multiply nodes in the material graph causes floating terrain ghost a ...
ShouldMarkSyncPhases causes pose discontinuities when sync leader changes
UE - Runtime - Anim BP - Aug 27, 2026The issue is caused by the way that we calculate the leader sample's Time vs the follower sample’s Time and how that calculation switches on the frame when a follower sample becomes a lead sample. ...
Body Setup of a Static Mesh with Simple Collision will pass validation, but removing it and using only a Complex collision and setting Collision Complexity "Use Complex as Simple" will fail validation: "Bone None requires at least one collision shape".
UE - Runtime - Character - Oct 20, 2025Context: By default, Unreal Engine creates both simple and complex shapes, then, based on what the user wants (complex query versus simple query), the physics solver will use the corresponding shape ...
Conflict between sequencer transform track and Parent Constraint from the Animation Mode breaks temporary pivot translation on any actor
UE - ACT Character - Anim in Engine - Jul 15, 2025Note: This affects all versions from at least UE 5.3, including mainline latest. The "Animation" Editor Mode allows creating constraints for level actors. One of these, the "Parent" constraint, con ...
Translucent materials in the PostMotionBlur pass can cause a flickering viewport artefact when using TAA
UE - Rendering - Features - Feb 5, 2025There appears to be a bug relating to rendering multiple windows that can trigger under unknown circumstances. It has been reported on rectangle lights in the forums and on PostMotionBlur materials ...
Wrong WPO motion vectors due to Periodic World Space node
UE - Rendering - Features - May 13, 2026We've noticed smearing in grass due to wrong motion vectors. This appears to be caused by lack of previous frame support in the periodic world space node. This is how we fixed it: In MaterialTempl ...