Crash when interacting with an Actor containing an Instanced Static Mesh that is in a Locked level

UE - Editor - Workflow Systems - Mar 30, 2023

This is not a regression. Tested in //UE5/Release-5.1 CL23901901 Editor crashes with an assertion after interaction with an Instance Static Mesh component that is in a locked level. This doesn't af ...

Crash occurs while playing in editor with a State Tree using Bool Compare for a transition state to a child state.

UE - AI - StateTree - Apr 25, 2023

This is a regression. Tested in //UE5/Release-5.1 CL2390901 The crash occurred 3/5 times. Crash occurs while playing in editor with a State Tree using Bool Compare for a transition state to a child ...

Preview rendering does not update when slider is moved below 0.0 in timeline on in Niagara Editor.

UE - Niagara - Jul 26, 2023

Workaround in UE5.3:  UNiagaraComponent::TickComponent             if (AgeDiff < 0.0f)             {                 SystemInstanceController->Reset(FNiagaraSystemInstance::EResetMode::ResetAl ...

VolumetricCloud crashes in orthographic view

UE - Graphics Features - Feb 17, 2025

FVolumetricRenderTargetViewStateData structure for the orthographic view is not initialized and the structure has some uninitialized member variables. If uninitialized FVolumetricRenderTargetViewSta ...

Sequence thumbnails save with visual issues

UE - Anim - Sequencer - Aug 1, 2025

[Link Removed] When camera tracks are activated, saving the sequencer results in captured anomalies: 1. Incorrect aspect ratio 2. Additional post-processing effects such as lens flare appear 3. ...

WorldToClip/ClipToWorld transform in materials not behaving as expected

UE - Graphics Features - Dec 19, 2025

In 5.3, the specified code will return all 0 or very small as expected. However in 5.4.4 and onwards (also checked in 5.6.1 & 5.7.1), it returns very large numbers. ...

Static Mesh Only enabled Foliage Actor causes serialization error in packaged game

UE - World Creation - Worldbuilding Tools - Nov 24, 2023

The crash can be worked around by modifying FFoliageISMActor::Serialize as following code : void FFoliageISMActor::Serialize(FArchive& Ar) { #if WITH_EDITORONLY_DATA     if (!Ar.IsCooking()) // ...

Crash when reverting to the default material in the static mesh editor

Tools - Apr 17, 2017

The editor crashes when attempting to revert the material on the cube back to default which is the World Grid Material. The cube is already set to WorldGridMaterial so I am not sure why the arrow ...

Assert cooking QAGame QA-Blueprints map with Nativization enabled

UE - Gameplay - Blueprint Runtime - Apr 18, 2017

When cooking QAGame (QA-Blueprints map) an assert is triggered during the cook step. So far I have reproduced this for: Win64 and PS4. ...

Editor crashed on opening level blueprint

UE - Gameplay - Apr 10, 2017

I've been unable to reproduce this issue. Once only occurrence so far. I did some other things inside the level in between these steps like pressing play and copying, rotating, deleting objects in ...