Out-of-Bounds Access During Partial Updates of ISMC Per-Instance Custom Data

UE - Graphics Features - Jan 6, 2026

When using instance custom data values, removing an instance and changing the number of custom data floats in sequence can cause an array-out-of-bounds crash. The underlying arrays are not resized ...

Sequential Level Loading in Python causes Crash

UE - Editor - Workflow Systems - Apr 16, 2019

Loading all the levels selected in the Content Browser and running the aforementioned Python script causes the editor to crash Tested in 4.20.3 (CL - 4369336), 4.21.2 (CL - 4753647), 4.22 (CL - 5 ...

LIVE: Code projects using TextureRenderTarget2D will not build because UTextureRenderTarget is undefined in TextureRenderTarget2D

UE - Foundation - Core - Nov 5, 2014

If a TextureRenderTarget2D is used in a code class, the build of the project will fail with an error stating that the UTextureRenderTarget base class is undefined. The line #include "Engine/TextureR ...

Client crash on seamless travel in DataReplication with lag

UE - Networking - Jan 11, 2016

When server traveling, client may crash due to lag while attempting to replicate object/property. ...

Assertion failed: PlatformNeedsExtraDeletionLatency()

UE - Rendering - Architecture - RHI - Mar 5, 2019

Animating a HISM along a spline when many other HISMs are present will result in a crash in 4.22. Confirmed in 4.23 MAIN @ CL 5291468 ...

Making changes to a Camera Shake while previewing the Camera Shake triggers a crash

UE - Anim - Sequencer - May 23, 2022

This is not a regression. Tested in //UE4/Release-4.27 CL 18319896  Making changes to a Camera Shake while previewing the Camera Shake triggers an Assertion upon compiling. ...

Crash when deleting the Add Component By Class node after changing the Relative Transform of the component

UE - Gameplay - Blueprint - Mar 31, 2021

When adding the Add Component By Class node, choosing a class that has a Relative Transform pin, changing the transform, and deleting the node the editor crashes. I tested this with the Skeletal Mes ...

Deleting elements from TMap Struct in actor blueprint editor causes Crash

UE - Editor - UI Systems - Slate - May 24, 2019

Deleting elements from TMap Struct in the Actor Blueprint Editor (specifically, deleting elements from them) causes Unreal to crash ...

Crash when calling an event with an enum reference parameter with literal

UE - Platform - Linux - May 1, 2018

The issue appears to be the type of the input pin on the custom event(or function - both behave the same), under normal circumstances it should allow you to pick the enum from a list on the calling ...

Editor crashes when keying a frame to an Animation from Pose with Appended Frames

UE - Anim - Runtime - May 17, 2022

This is a regression. Tested in //UE4/Release-4.27 CL18319896 Editor crashes when keying a frame to an Animation from Pose with Appended Frames. ...