Sub-world partitions do not properly handle partial editor loading as world partition standalone level instances' spatially loaded actors do not get loaded even when the Level Instance is force loaded or loaded in by region.

UE - World Creation - Worldbuilding Tools - World Partition - Aug 19, 2025

Context Level Instancing is a level-based workflow designed to improve and streamline the level editing experience. In a standalone Level Behavior, when the Level Instance Actor is loaded through it ...

[CrashReport] <unknown module>!UE4Editor_Core!FDebug::AssertFailed()

UE - Foundation - Core - Mar 28, 2016

Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 678] Array index out of bounds: 0 from an array of size 0 Source Context: 80 } 81 else ...

iOS CloudKit Crash

UE - Platform - Mobile - Dec 12, 2019

iOS app crashes when cloudsaves are active When attempting to deploy with 4.25 MAIN @ CL 10668484 it fails with error LogPlayLevel: === BUILD TARGET AJ_ioscloudsave OF PROJECT AJ_ioscloudsave WI ...

Crash when resizing window using Quad Stereo Buffer

UE - Virtual Production - nDisplay - Oct 2, 2019

We noticed crashes in our application when we attempted to resize a window or switch to full-screen mode. Hence, resizing windows and switching to full screen will result in a crash on Unreal Engine ...

Custom iOS icons don't appear on device for Windows BP projects (Binary Build)

UE - Platform - Mobile - May 4, 2018

iOS icons have stopped working for Windows BP projects again; this does not occur on Mac. It also does not occur when using a source build from p4 (only on a binary build from the launcher). Note t ...

Crash Importing some assets with "Keep Overlapping Vertex"

UE - Editor - Content Pipeline - Import and Export - Nov 29, 2016

Download offending asset here: [Link Removed] Error message: Assertion failed: NewPosition >= 0 [Link Removed] [Line: 452] Source Context: 438 virtual ~FFileHandleWindows() 439 ...

Editor Crashes When Updating Captures on Sphere Reflection Captures

UE - Graphics Features - Feb 20, 2017

Error 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 ...

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 ...

Crash Occurring in FD3D11DynamicRHIModule::FindAdapter()

UE - Graphics Features - Jul 13, 2016

Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 804] Array index out of bounds: 1 from an array of size 1 Source Context: 352 353 // We a ...

Ensures in ChaosExamples_fracture map in ChaosDestructionDemo

UE - Simulation - Physics - Destruction - Jun 4, 2019

Ensures trigger when playing in the ChaosExamples_fracture map in the ChaosDestructionDemo project. The ensures seem to happen during different parts. A couple occurrences were when I triggered th ...