ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision

UE - Simulation - Physics - Jan 27, 2025

ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision. The licensee reports one of their users reported this issue and they were able to reproduce a fe ...

Reset to default behavior for arrays is inconsistent about updating customized struct headers

UE - Editor - Workflow Systems - Jun 22, 2023

The behavior for resetting the default for customized struct properties is inconsistent and needs to be reviewed and fixed. Currently we see this behavior:In non-array properties, the header will be ...

Force Next Floor Check doesn't work when the player is stopped

UE - Gameplay - Player Movement - Oct 6, 2016

Force Next Floor Check doesn't work when the player is stopped, even though the tool tip says that it does. User Description: I'm trying to shrink / grow the collision capsule for our needs but wh ...

Inconsistent ListView entry sizes can prevent the ListView from being scrolled to the bottom

UE - Editor - UI Systems - Slate - May 4, 2022

Since the contents of a ListView are virtualized, the ListView estimates the size of the scroll box's contents based on the on-screen elements. This can lead to some situations where DistanceFromBot ...

Composite font uses a sub-font, even when the sub-font doesn't support the character

Tools - Apr 7, 2016

I have a fix for this shelved in CL# 2937344, so it would be good to get it into 4.12 once the user verifies the fix. ...

Crash when trimming animation and then undoing action

UE - Anim - Runtime - May 30, 2023

Repro rate: 3/3 times This is a regression as the issue does not occur in 5.1.1  ...

MotionWarping does not recognize new MontageInstance with the same montage

UE - Anim - Gameplay - Jan 11, 2023

When the same AnimMonotage is played again while moving with MotionWarping & RootMotion, UAnimNotifyState_MotionWarping does not recognize it. From licensee: The issue was that in URootMotionMod ...

After breaking a level instance without Actor Folders, moving its actors between folders of the world-partition map does not work correctly

UE - World Creation - Worldbuilding Tools - World Partition - Jan 29, 2024

If a standard level (without Actor Folders enabled) is added to a world-partition map (with Actor Folders enabled) as a Level Instance, and then that instance is "broken" so that its actors are inco ...

Exception on missing fiile during GC in horde storage

UE - Foundation - Horde - Storage - May 7, 2025

During GC, if a file was manually deleted (but the storage system is still track), GC can erroneously fail (and never remove the reference). This causes a backup in GC, putting the whole algorithm i ...

FBX: Camera imports to Matinee with skewed position and rotation

UE - Editor - Content Pipeline - Import and Export - Aug 27, 2013

Branch Build Label Changelist UE4-Main UE4_[2013-08-27_14.24] 1799942 DESCRIPTION: When importing an animated camera from Maya into Matinee, the placement of the camera is changed (shifted 90 ...