Undo and ConstructionScript break the AttachChildren array

UE - Framework - Components - Nov 14, 2019

Undo fills AttachChildren array with null by the undo serializer. After that, a construction script tries to remove child components from parent component's AttachChildren but it can't find its poi ...

FInstancedStruct member uproperties are not cached when "Generate Optimized Blueprint Component Data" is enabled

UE - Framework - Blueprint - Nov 18, 2025

A licensee has encountered an issue where their FInstancedStruct isn't being gathered into CachedPropertyData when "Generate Optimized Blueprint Component Data" is enabled. The changes in ...

Pilot actor no longer generates undo transactions

UE - Editor - Jan 22, 2024

The piloting feature in the editor viewport is not undoable with Ctrl+Z It also does not cause the actor to become dirty so any changes during piloting are lost and not saved (user also not prompted ...

Haptic Effects do not fire on Vive controllers

UE - Platform - XR - Mar 5, 2016

Playing haptic effects via the associated blueprint nodes (I.e. Play Haptic Effect, or Set Haptics by Value), does not trigger any feedback on the Vive's motion controllers. This does not reproduce ...

[CrashReport] AppleIntelBDWGraphicsGLDriver!USC::CPassSsaAllocatorContext::RollbackSpillFillToCopies()

UE - Platform - Apple - Sep 2, 2016

Error message: SEGV_MAPERR at 0x3a Source Context: Most recent user affected CL: 3106830 (4.13.0) Logs: [Link Removed] [Link Removed] [Link Removed] CrashReporter User Descriptions:UE4.13 immed ...

Editor freezes when using multiple Post Process Volumes with Cubemaps assigned

UE - Graphics Features - Jun 13, 2016

When using a cubemaps assigned to a Post Process Volume and loading the level the editor will freeze if it's been a project converted from 4.11 to 4.12/4/13. In some instances if the camera is outsi ...

Capsule Indirect Lighting with ILCQ Volume breaks on Skeletal Meshes when making Sublevel visible not in the current Camera Frustum

UE - Graphics Features - Apr 12, 2017

When using Capsule Indirect Shadows for Skeletal meshes who have their ILCQ set to Volume, and loading a SubLevel with it's actors not within the current camera's view, the indirect lighting is blac ...

Packaging that involves a compilation process causes custom icons to not show in the taskbar on Windows in Binary

UE - Foundation - Cpp Tools - UnrealBuildTool - Nov 30, 2018

Packaging that involves a comilation process in the Binary editor causes custom Windows icons to be ignored in packaged games. This could either be seen in a Code project or in a Blueprint Only proj ...

Internal Compiler Error: Tried to create a property Crash in scope Beta_C, but another object (ObjectProperty /Game/Alpha.Alpha_C:Crash) already exists there.

UE - Gameplay - Blueprint - Oct 31, 2019

After fixing the crash from [Link Removed] when compiling the child blueprint that has claimed the component name the parent was previously using without having compiled the parent, an internal comp ...

tvOS encounters failure to read save file when loading saved level

UE - Platform - Mobile - Nov 20, 2019

When load is called user encounters: [UE4] [2019.11.20-23.42.09:282][575]LogStreaming: Warning: Failed to read file '../../../QAGame/Saved/SaveGames/TestSlot.sav' error. The integer value does not ...