Drag and Drop fails in Standalone and Packaged builds when WidgetComponent’s Widget is set at runtime

UE - Editor - UI Systems - Dec 4, 2025

When a UWidgetComponent has its widget assigned dynamically at runtime using CreateWidget and SetWidget, drag & drop operations fail in Standalone Game and packaged/game builds, while working correc ...

Custom thumbnails don't get updated until the asset is saved

UE - Editor - Workflow Systems - Dec 4, 2025

This is a regression, here's the repro in FN/Main (48954958) : [Link Removed] And now in UE5.7 (48496583) : [Link Removed] ...

Mover plugin: Crash on UFloorQueryUtils::ComputeFloorDist() and other utility functions that assume the pawn uses a UCapsuleComponent

UE - Gameplay - Player Movement - Mover - Dec 4, 2025

The following functions have been found to perform unchecked casts of the pawn's "UpdatedComponent" to class UCapsuleComponent, possibly resulting in crashes:UFloorQueryUtils::ComputeFloorDist()UGro ...

Unreal Engine Fails to Launch with Vulkan SM6 RHI and RenderDoc Auto-Attach Enabled

UE - Rendering - Architecture - RHI - Dec 3, 2025

When launching Unreal Engine with the Vulkan RHI, SM6 and RenderDoc Auto Attach on Startup enabled, the engine fails to initialize with the error: “A compatible Vulkan Driver is required to run the ...

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 ...

PIE also rendering in-active / unfocused editor viewport

UE - Rendering - Graphics Features - Nov 28, 2025

In 5.8, after entering PIE, the editor will start doing two SceneRenders per frame. This dramatically drops performance. Presumably this second render is for the inactive / unfocused editor viewport ...

SaveGeneratedTexture2DAsset can crash when overwriting an existing asset

UE - Texture - Nov 28, 2025

SaveGeneratedTexture2DAsset can crash for a variety of reasons when overwriting an existing texture asset. When no existing asset exists, the function simply moves the provided transient Texture ass ...

Crash when Live Coding is triggered after engine source edits Blueprints using ChildActorComponent

UE - Framework - Blueprint - Nov 28, 2025

After editing engine source files and triggering Live Coding, derived Blueprints that inherit from a Blueprint containing a ChildActorComponent cause UChildActorComponent::Serialize to run on a Live ...

FBX Import - Morph target normals not correctly applied when imported as LOD 0

UE - Editor - Content Pipeline - FBX - Nov 27, 2025

This is a regression since 5.5 with skeletal meshes where morph target normal/tangent deformation only works when a mesh is imported as a LOD of an existing skeletal mesh, but not when imported as L ...

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 ...