UInstancedStaticMeshComponent::AddInstances does not appear to be adding per-instance previous transforms when enabled

UE - Rendering - Graphics Features - Dec 3, 2025

Instanced static mesh component does not add instances transforms to PerInstancePrevTransform array when using UInstancedStaticMeshComponent::AddInstances. Additionally Updating the transforms of th ...

DoDeferredRender will not UpdateBound correctly when NavigationCachedBoundsUpdated

UE - AI - Navigation - Dec 2, 2025

With InstancedStaticMeshComponent, after calling AddInstance, an instance that’s far away gets culled because of additional logic that was added in 5.7 to This works correctly in 5.6 and the instanc ...

Material LocalPosition node does not work correctly with Nanite Skinned meshes

UE - Rendering - Graphics Features - Dec 1, 2025

Nanite Skinned Meshes don't receive the correct Local Position in some shadow passes. This depends on the clipmap level, and is not related to VSM caching. Unreal Engine 5.6 shows the same issue, b ...

In 5.7, a Sequencer that contains a Spawnable ChaosCacheManager will crash the Engine on EndPlay

UE - Simulation - Core - Nov 30, 2025

In 5.7, a Sequencer that contains a Spawnable ChaosCacheManager will crash the Engine on EndPlay. The licensee has reported, and I've confirmed, that this behavior started in 5.7. I've confirmed thi ...

Initialization error when creating FEventReply objects from Python

UE - Editor - UI Systems - UMG - Nov 28, 2025

the handled value passed to unlock_mouse is actually treated as unhandled, because FEventReply has no uproperty and no Identical()function of its own. Adding WithIdenticalViaEquality can fix this is ...

Translucent Wireframe Materials Exhibit TSR Aliasing/Crawling Due To Incorrect Velocity Rendering When Set to Output Depth And Velocity

UE - Rendering - Graphics Features - Nov 27, 2025

Note that this bug potentially also affects a wide variety of material / geometry setups; however, a translucent wireframe setup is currently the main reproduction case. The issue may also be notice ...

Control Rig Creation Crash Triggered by “skel” Prefix in Skeletal Mesh Name

UE - Anim - Rigging - Control Rig - Nov 27, 2025

When generating a Control Rig from a Skeletal Mesh that contains “skel” in its name—or uses it as a prefix (i.e. skel_test)—Unreal Engine crashes. The crash occurs both when using the native Creat ...

The bake_transform_with_settings method works in 5.6 but not 5.7

UE - Anim - Sequencer - Nov 26, 2025

Trying to automate the process of baking transforms via python and the identical code above works in 5.6 but not in 5.7. There are no error messages in the output log. When running in 5.7, it does ...

HLOD generation can run out of space in the FName table

UE - World Creation - Worldbuilding Tools - Nov 26, 2025

A licensee reported that generating the HLOD for his large WP based level is running out of space in the FName string table.  He tracked the source of the problem to CL 47064601. Upon inspection ...