[AI] Debug Render Scene Proxy hits ensure for registering a delegate twice during level streaming.

UE - AI - Debugging - Aug 31, 2022

Description from licensee: We're seeing an ensure get tripped up in FDebugRenderSceneProxy that says "DrawDelegate is already Registered!". Debugging the issue, we have confirmed that the DrawDeleg ...

Merging Splines causes Engine to Crash in 5.1

UE - World Creation - Worldbuilding Tools - Merge Actor - Dec 15, 2022

Attempting to merge two spline actors causes the Engine to crash. This issue occurs with the Steps to Reproduce regardless if there are more branches added to the tree branch spline/enabled, and reg ...

Interchange framework is bypassed on the second attempt after a failed import

UE - Editor - Content Pipeline - Import and Export - Jul 14, 2025

Hello! We have encountered a bug with the Interchange pipeline. When an interchange texture import is cancelled due to non-power of 2, and then the same texture is imported again without any change ...

Chaos : Rigid body sleeps when very small external force is applied by AddForce

UE - Simulation - Physics - Solver - May 25, 2022

When a small external force is applied to the rigid body, the VSmooth value is reset in the ResetVSmoothFromForces function. Since this function ignores the current velocity, a very small velocity ...

ConfigContext on linux requires perforce path for defaults.global.json when global is perforce resolved

UE - Foundation - Horde - Server - Mar 7, 2025

As of 5.5.2; appears present in main head as well. We have a asymmetry between how Include JSONs are resolved between Linux and Windows. This boils down to our URI construction in ParseIncludesAsyn ...

Pressing the "Show Inactive" button in the material instance editor did not display groups that did not contain the active parameter

UE - Rendering Architecture - Materials - Aug 1, 2024

When pressing the "Show Inactive" button in the material instance editor, all material parameters are supposed to be displayed in the EditorUI. This is not the case, only some of the parameters are ...

Asset returns after being deleted from the content folder while the editor is open

UE - Editor - Content Pipeline - Content Browser - May 8, 2017

Asset returns after being deleted from the content folder while the editor is open. A deleted asset comes back and does not prompt to save it. This leads to the asset being removed when the editor i ...

[CrashReport] Assertion failed: !PinRef->bWasTrashed | UEdGraphPin::SerializePin()

UE - Gameplay - Blueprint - Aug 29, 2017

This is a common and longstanding crash that has occurred since at least 4.15 and affected nearly 500 users. The CrashGroup was previously linked to [Link Removed], but that had specific repro step ...

Niagara Simulation Stage + DynamicMaterialParameters crash

UE - Niagara - Feb 6, 2021

deleting the code "&& SimulationStages[i]->bEnabled" in UNiagaraEmitter::GetScripts will bypass the problem [Image Removed] ...

[CrashReport] UE4Editor_ShaderCore!FVertexFactory::Set() [vertexfactory.cpp:180]

UE - Graphics Features - Jul 5, 2016

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Source Context: 165 return *VertexFactoryTypeIt; 166 } 167 } ...