FBX import freezes in DataPrep

UE - Editor - Content Pipeline - Visual Dataprep - Mar 3, 2025

FBX file import freezes UE while trying to import into DataPrep by the Interchange importer. The import will start, but then a message will pop up stating "Creating snapshot of world content ... " ...

Chaos Mover crash in standalone editor client

UE - Runtime - Character - Aug 18, 2026

When using the Chaos Mover with resimulation enabled, standalone editor processes running as a client will crash around 80% of the time upon startup. ...

Unreal Editor can get in an infinite while loop when checking the History of an asset under Perforce.

UE - Editor - Oct 21, 2024

Unreal Editor can get in an infinite while loop when the action Asset->Source Control->History is used in a Blueprint Asset. Reportedly, this issue is only encountered when using the Branches featur ...

GameCenter does not login on Match3 startup on iOS

UE - Platform - Mobile - Aug 23, 2016

When launching on or opening a packaged UnrealMatch3 project GameCenter does not login for the paired account. This causes Leaderboards and Achievements to appear blank. Tested on iPhone6s_6240 OS: ...

Crash after changing either the Anim Start or End times of an Animation Composite

UE - Runtime - Animation - Jul 19, 2022

This is a regression tested in //UE4/Release-4.27 CL#18319896 Crash after changing either the Anim Start or End times of an Animation Composite when using Enter to confirm their value. ...

Crash with SceneCapture DepthPrepassOptimization enabled

UE - Rendering - Architecture - May 22, 2026

Level asset "Diff against depot" opens P4 Merge tool

UE - World Creation - Worldbuilding Tools - Mar 1, 2024

You can right click a level asset in the editor's Content Browser and do the action Source Control > Diff against Depot. However, this does not provide a useful diff window. It currently opens the d ...

Crash when entering Brush Editing mode with a Sequence spawnable Post process volume

UE - Graphics Tools - Modeling Tools - BSP - Mar 18, 2024

Crash with Assertion failed shortly after launching packaged First Person CPP project on Oculus Mobile - Referencing SparseArray.h:86/87

UE - Platform - XR - Apr 30, 2019

The following assertion throws after the project crashes when playing on the device: Assertion failed: Index < GetMaxIndex() [File:D:/P4Workspaces/Switch_3/Engine/Source/Runtime/Core/Public/Contai ...

Destroying a welded actor is causing an Array index out of bounds crash on 5.6

UE - Runtime - Simulation - Jul 30, 2025

Destroying a welded actor is causing an Array index out of bounds crash on 5.6. The licensee has provided a repro project that reliably causes a crash whenever the spawned actor is destroyed. There ...