BP - Nativization will fail at cook time if a BP class and a User-Defined Structure reference each other.

UE - Gameplay - Blueprint - Apr 20, 2017

Note: This happens with "Exclusive" nativization mode as well. This occurs because the nativized UDS 'GetDefaultValue()' method is generated into a .h file rather than a .cpp file. This creates a c ...

Loading Duplicated Level via Python API Crashes Editor

UE - Editor - Workflow Systems - Feb 16, 2023

When called from Python, in 5.1 the load level invocation results in a kernel panic style crash of the editor, with a message about the map leaking memory and not being able to be garbage collected ...

Crash after generating HLODs for approximated meshes that have all triangles culled

UE - World Creation - Worldbuilding Tools - HLOD - Apr 26, 2023

The crash occurs when FWorldPartitionHLODUtilities::BuildHLOD attempts to build an approximated mesh that has all of its contents culled during generation, this can happen when an approximated mesh ...

Crash during shader compilation when r.Shaders.Optimize=0

UE - Rendering Architecture - Shaders - Mar 11, 2024

The primary shader crashing is "FVisualizeLumenSceneCS" which I've put in the callstack section, but I think this is more likely a binding problem as I'm also see the following crash with cloud shad ...

Crash using a bitmap in a material

TM - Core - Mar 3, 2025

see repro steps: direct crash the material comes from FAB model:  [Link Removed] ...

[AI] Crash when gathering heightfield geometry on worker thread

UE - AI - Navigation - Jun 25, 2025

From the body of the ticket: We aim to do as much of the work off the game thread as possible to avoid impacting frame rate. We've recently found a crash during collection of the geometry slices fr ...

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. ...

Launch on fails during staging with a SafeCopyFile Exception for MfMedia.uplugin

Tools - Jan 10, 2017

Was able to repro this on machines with and without machines set up for Xbone testing. ...

Crash Occurs When Creating Pose Asset from an Animation in Persona

OLD - Anim - Feb 1, 2018

Engine crashes when creating a new pose asset in persona using the Create Asset option -Tested with walk, idle, and run anims -Didn't crash only once out of the several times tested with the Third ...

Swapping the C++ Root Component from a Child BP class, pressing Save, Compile, but not Saving afterwards, will leave the Root Component in a locked state, meaning the it cannot be viewed or edited in the Details Panel after an Editor restart

UE - Framework - Blueprint - Dec 9, 2024

Swapping the C++ Root Component from a Child BP class, pressing Save, Compile, but not Saving afterwards, will leave the Root Component in a locked state, meaning the it cannot be viewed or edited i ...