Crash Occurs When Actors are Attached Across Persistent and Sublevels When Levels are Saved

UE - Anim - Sequencer - Dec 12, 2017

Can attach actors to each other through the use of sequencer even though actors are in different levels which leads to crashing when saving and changing levels F3DAttachTrackEditor::IsActorPickabl ...

FBX Transform does not scale skeletal mesh with multiple pieces properly using the Import Uniform Scale option

UE - Editor - Content Pipeline - Import and Export - Aug 15, 2016

Importing a skeletal mesh fbx from blender and setting the Import Uniform Scale option for the mesh to a higher value, like 100, results in only one of the meshes being scaled while the other is lef ...

Rear tires on vehicle in VehicleGame sample detach and drift back from axel as user accelerates

OLD - Anim - May 3, 2017

This is a regression from 4.15 as it is unreproducible on a binary build in //UE4/Release-4.15 @ 3416026. Both my 4.15. and 4.16 versions were obtained from the EGL. The more the higher the speed t ...

SunTemple scene does not update properly on iPhone 6S

UE - Platform - Mobile - Jul 18, 2017

On the 6S, the SunTemple scene is almost unresponsive. As the player uses the thumbsticks, the lightmaps from the windows rotate to mach the player's movement; but they are the only thing. This doe ...

Copy/pasting component results in broken duplicate component (named _GEN_VARIABLE)

UE - Gameplay - Components - Jul 28, 2017

REGRESSION: Yes. Does not occur in 4.16.3 Using Copy/Paste to duplicate a component will result in a broken duplicate component. This doesn't occur if the user uses Ctrl+W to duplicate. On compi ...

Certain combined Linear/Angular movements cause Client to freeze for several seconds

UE - Simulation - Physics - May 24, 2019

When using Replicated Movement, certain combined linear/angular movements cause the client to freeze for several seconds and then catch up to the server. This is a regression from 4.21.2 (CL-4753647 ...

NavModifierVolume's FailsafeExtent is applied to the wrong area

UE - AI - Apr 16, 2020

The FailsafeArea of NavModifierVolume is generated at a different location from the center of the actor when it rotated. This means that the effect of rotation is incorrect. (see attached file) W ...

BuiltData is saved alongside it's map, even if lighting hasn't changed

zComponent - Archive - Jun 25, 2021

Saving a map will always resave the map's BuiltData, even if the BuiltData hasn't been marked dirty. Changes were made to avoid marking it dirty for UE-96057, but the call to SaveWorld in FEditorFil ...

bIgnoreAllPressedKeysUntilReleaseOnRebuild in Enhanced Input behaves unexpectedly during pawn possession

UE - Gameplay - Input - Jun 11, 2025

This is a speculative bug report from the user.  The fix for this is to re-do the work of 31224705 but in a better way. The "bShouldBeIgnored" flag is being overriden by the previous mapping's va ...

Crash in Retarget Manager with Humanoid Rig when trying to re-assign a bone to a node

OLD - Anim - May 26, 2015

Crash in the Retarget Manager with Humanoid Rig when trying to re-assign a bone to a node. Happens particularly when there is already a bone selected and you want to select a new one. [Link Remove ...