Import then cancel while file is read leads to potential crash

TM - Interoperability - Oct 6, 2025

1/ Import a file with mootools such as an fbx 2/ while the file is still read, cancel the import Result : may crash few times after (when theoretically the file has finished being read) - not repr ...

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 ...

[CrashReport][Assert] UnrealEditor-RHI!FRHIResource::MarkForDelete() [Engine/Source/Runtime/RHI/Private/RHIResources.cpp:49]

UE - Rendering - Architecture - Materials - Dec 18, 2024

One of the users described this issue as below. "At seemingly random times while working in the material graph, some action will cause a hitch or freeze, and quickly after the engine will crash, an ...

Player Character does not collide with landscape

UE - LD & Modeling - Terrain - Landscape - Mar 8, 2015

UPDATE: 3/9/2015 Additional Information: User on thread https://answers.unrealengine.com/questions/186928/landscape-collison-issues-recreatelandscapecollisi.html reported workaround did not fix e ...

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 ...

Crash after creating a suboject for RootComponent if the actor is placed on the level

UE - Foundation - Cpp Tools - Hot Reload - Nov 6, 2020

The crash occurs when trying to assign a new value to RootComponent if the Pawn is already placed on the level Crash does not happen in  P4 //UE4/Release-4.25.3 CL 13942748 Other steps to reproduc ...

Incorrect Velocity Calculation at Animation Sequence Transitions in Level Sequence

UE - Anim - Sequencer - Feb 18, 2025

When adding an Animation Track to a Level Sequence and placing Animation Sequences back-to-back without gaps, the velocity can be miscalculated at the transition between sequences. This issue occur ...

World Partition - Deleted actors can become unloaded prior to saving

UE - World Creation - Worldbuilding Tools - World Partition - Apr 11, 2025

In world partition levels, deleted actors can become unexpectedly unloaded prior to saving, causing loss of work. Specifically, this issue occurs after the undo history has been cleared (either manu ...

GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues

UE - Simulation - Visual - Aug 30, 2025

GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues. The licensee has provided their analysis: We seem to have stumbled acro ...