20 FPS performance drop between 4.7.6 and 4.8 on devices rendering Metal only

UE - Platform - Mobile - Jun 22, 2015

User reported a considerable performance drop on iOS between versions 4.7.6 and 4.8. I was able to reproduce this perf drop using the steps he provided. ...

Deadlock in UAnimationSequencerDataModel::Evaluate where FScopeLock Lock(&EvaluationLock) blocks execution indefinitely

UE - Anim - Nov 4, 2025

When both the Sequencer Editor and an Animation Curve Editor are open for the same animation asset, the editor freezes completely upon editing the curve. Analysis indicates that the freeze is caus ...

Crash occur when loading AInstancedPlacementPartitionActor

UE - Editor - Workflow Systems - May 17, 2022

Crashes when loading an actor that inherits from AInstancedPlacementPartitionActor. There is a serialization size mismatch. ...

Crash when enabling Level of Detail Coloration viewmodes in the Dataprep editor while using DX12

UE - Rendering Architecture - RHI - Dec 2, 2019

Crash when enabling Level of Detail Coloration viewmodes in the Dataprep editor while using DX12 This crash does not occur when the project is opened with DX11. Note that the Dataprep editor does ...

When show propertymatrix and delete target actor, the editor crash

Tools - Jul 11, 2017

It looks like it is null reference in propertymatrix. It always occurs when I execute the reproduction procedure. ...

Planar Reflections on Mobile short view distance for non single plane faces

UE - Platform - Mobile - Jul 7, 2016

Planar Reflections on mobile work well with single plane assets but not with anything with multiple sides, like a box. Tested in: 4.12.4 CL-3028348 4.13 Dev-Editor CL-3038075 ...

Planar Reflections do not respect SkyLight intensity

UE - Graphics Features - Nov 14, 2017

Planar Reflection actor does not reflect the intensity change of the SkyLight. In attached images, the Intensity of the SkyLight is set to 2. The darker area on the right is affected by the Plana ...

[Review Tool] The editor crashes while attempting to load a modified Blueprint that uses Interface for review.

The crash is due to previous Rename operation, that reset a preallocated array which later FAsyncPackage2::ExecuteDeferredPostLoadLinkerLoadPackageExports tries to use.  Before loading change list ...

Pasting custom data floats from a text editor into a instanced static mesh component crashes the editor

UE - Framework - Components - Aug 5, 2024

When an instanced static mesh component with a material using a PerInstanceCustomData node has its data floats pasted in, the editor crashes with an "Array index out of bounds" error. The licensee w ...