SSR doesn't reflect Skydome Mesh/Material correctly in Vulkan mobile preview

UE - Platform - Mobile - Aug 4, 2025

5.6[Image Removed] 5.5[Image Removed][Link Removed] ...

Switching modular control rig to FK mode breaks pose of controls that have been baked to rig

UE - Anim - Rigging - Control Rig - Sep 14, 2025

From the licensee:We have built a modular Control Rig in Unreal 5.6, and while IK to FK matching works correctly inthe rig, but we are facing an issue when applying mocap animation to the characters ...

[CrashReport] UE4Editor_Engine!UAnimMontage::IsValidAdditive() [animmontage.cpp:702]

OLD - Anim - May 19, 2016

Error message: Stack overflow - code c00000fd (first/second chance not available) Source Context: 687 if (SyncGroup != NAME_None) 688 { 689 CollectMarkers(); 690 ...

TInstancedStruct used in native actor class loses reference to Instanced UObject after BP recompilation

UE - Framework - Blueprint Compiler - Jun 25, 2025

When a TInstancedStruct contains a UObject marked with EditInlineNew and DefaultToInstanced, the reference is lost after compiling the Blueprint but only when the struct is part of a native Actor cl ...

Direct Capsule Shadows with Point Lights also project shadow on opposite side and direction

UE - Graphics Features - Dec 14, 2016

When using a Direct Capsule Shadows on a skeletal mesh with a Stationary Point light, depending on the point lights placement, light source radius, and nearby surfaces will cast the shadow on the op ...

Bake To Control Rig on a Spawned Actor in a Subsequence with Play Range that exceeds the Subsequence causes a Crash

UE - Anim - Anim in Engine - Jun 28, 2023

This is a Regression. Tested in //UE5/Release-5.1 CL23901901 Using Bake To Control Rig on a Spawned Actor in a Subsequence with Play Range that exceeds the Subsequence causes a Crash. ...

LayeredBlendPerBone without BlendRootMotionBasedOnRootBone exaggerates root motion

UE - Anim - Runtime - May 27, 2023

When BlendRootMotionBasedOnRootBone is false, the LayeredBlendPerBone is aggregating root motion of the child poses ontop of the base pose root motion.  (ie. if the first child pose's blend weight i ...

Build failure after nativizing any child Blueprint class with function override (regression).

UE - Gameplay - Blueprint - Jun 7, 2018

Nativization regression in 4.20 preview 1. Cannot nativize overridden functions. Log Output:UATHelper: Packaging (Windows (64-bit)): D:/Projects/Unreal/NativizeMethod/Intermediate/Plugins/Nativized ...

Control Rig: crashes when compiling after rearranging input pins in an array in Example Rig Unit

OLD - Anim - Aug 20, 2019

The crash doesn't occur every time, but it will happen within 3 swap and compiles in my experience. I got multiple different callstacks when I cause the crash using the reproduction steps (they are ...

Failed to generate Nanite data for mesh with bDoFastBuild enabled

UE - Graphics Features - Nanite - Oct 1, 2025

If "bDoFastBuild" is enabled on a Static Mesh asset, in-editor it will never be able to have Nanite data built for it, preventing the Static Mesh from using Nanite. There is no way to fix this issu ...