Unreal Engine Issues
Unreal Engine Issues
Editor Crashes When Updating Captures on Sphere Reflection Captures
UE - Graphics Features - Feb 20, 2017Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 633] Array index out of bounds: -1 from an array of size 11 Source Context: 200 CubemapArray.Updat ...
HZB Occlusion causes large stalls on the render thread
UE - Rendering Architecture - RHI - Oct 7, 2025HZB Occlusion causes large stalls (greater than 5ms seen) on the render thread due to an RHI flush. This is caused by the following code in FDynamicRHI::RHIMapStagingSurface_RenderThread which force ...
Naming a Blueprint function/graph with non-ASCII characters can cause a build failure for certain cooked targets when Blueprint nativization is turned on.
UE - Gameplay - Blueprint - Nov 2, 2017This is due to the [Link Removed] encoded UFunction object name passing through UHT into the boilerplate code (*.gen.cpp) that gets generated from the nativized Blueprint's C++ header file. The iss ...
Form Extended Structures will only destroy one mesh but not any attached
UE - Simulation - Physics - Destruction - Nov 28, 2014DESCRIPTION: While using form extended structures enabled for a Destruction mesh one of the meshes will be able to be damaged while any others attached will not fracture or damage at all. For exam ...
Actors in sublevels do not replicate to Clients after Seamless ServerTravel
UE - Networking - Dec 9, 2015Actors in sublevels do not replicate to Clients after Seamless ServerTravel. The user reporting this noted that "[...] UNetDriver::IsLevelInitializedForActor() keeps returning false even when the ac ...
[Interchange] Crash on asset re-import
UE - Editor - Content Pipeline - Import and Export - Feb 7, 2025We've started seeing a crash in editor when re-importing one of our assets. <pre class="ql-syntax">Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 783] Array index out of ...
LIVE: RENDERING: Movable Mesh does not receive shadows from Static meshes in static or stationary lighting
UE - Graphics Features - Apr 30, 2014---------------------------------------------------------------------------------------------------------------------- Build: 4.1.0-2057451 Description: Movable meshes and blueprints set to cast n ...
MoviePipeline: Incorrect Caching of Min/Max World Delta Time
UE - Anim - Sequencer - MRQ - Jan 31, 2023To test this issue: Create a C++ class WolrdTimeDilationDebugActor.h in your Project with the following code:// Copyright Epic Games, Inc. All Rights Reserved. #pragma once #include "CoreMinim ...
Installed builds of the Engine cannot package game targets with optional game features
Tech - BuildOps - Infra - Mar 10, 2022The build system supports many types of flags that can be enabled in game-specific Target.cs files to enable things like logging in shipping, target-specific overrides like custom config, or enablin ...
[AI] Bad entries in NavigationRepository for Box collision with bCanEverAffectNavigation set to false
UE - AI - Navigation - Oct 26, 2025Some components continue to dirty the navigation state even if bCanEverAffectNavigation is unchecked. Behavior appears very similar to an existing bug, [Link Removed] ([Link Removed]), which invol ...