[PCG Mode] Tool actors spawned by PCG Editor Mode tools ignore the current level and are always created in the PersistentLevel

UE - Graphics Tools - PCG - Procedural Tools - Oct 21, 2026

Summary In a non-World-Partition map with streamed sublevels, PCG Editor Mode interactive tools (Draw Spline / SpacingTool, Area, Paint, Volume, ...) spawn their new tool actor in the PersistentLevel ...

Crash in AWorldDataLayers::InitializeDataLayerRuntimeStates() when quickly unloading then loading a sub-world partition

UE - Engine Scaling - Streaming - Data Layers - Mar 6, 2025

From licensee: Since we integrated 5.5, we are experiencing a crash in AWorldDataLayers::InitializeDataLayerRuntimeStates() on this line check(ActiveDataLayerNames.IsEmpty() && LoadedDataLayerN ...

Crash on iOS9 when using Apple's CFNetwork library

UE - Platform - Mobile - Dec 6, 2016

Many clients have hit a crash due to an Apple library using operator delete on a memory block that was not allocated with operator new. This happens with the following callstack on iOS9 in UE4.13 o ...

Loading a blueprint with an invalid gameplay tag container pin causes ensure and data loss

UE - Gameplay - Feb 23, 2021

The gameplay tag system depends on tags being registered with the global manager as valid in order to correctly read them off disk. Two different issues are combining to cause a confusing ensure and ...

If using SetAlignmentInViewport in Construct, the value with it is ignored

UE - AI Workflows - UI Systems - UMG - Jan 27, 2023

If SetAlignmentInViewport is called in the UMG Construct, it is ignored internally. This is due to a change that came in 5.1, so it worked fine in 5.0. First, when the Set Alignment in Viewport nod ...

WP HLOD Crash on Small Cell Sizes

UE - Engine Scaling - Streaming - HLOD - Jan 8, 2024

Launching QAGame for HTML5 creates an 'uncaught exception: out of memory'.

UE - Platform - Mobile - Jan 18, 2017

Launching onto HTML5 opens the browser to Uncaught Exception: out of Memory After running it on a 64-bit browser, the following is printed:uncaught exception: abort("Cannot enlarge memory arrays. E ...

[CrashReport] UE4Editor_SlateRHIRenderer!FSlateRHIResourceManager::GetShaderResource() [slaterhiresourcemanager.cpp:525]

UE - Editor - UI Systems - Slate - Nov 2, 2017

This is a trending crash coming out of the 4.18 release, and may be a regression. Users have not provided any descriptions of their actions when the crash occurred. Jiras for similar callstacks in ...

[UE 5.8][MediaViewer] Crash when switching Level Editor viewport type to Cinematic Viewport

UE - CAPT - Tools - Media Viewer - Oct 19, 2026

POST LINK: https://forums.unrealengine.com/t/ue-5-8-mediaviewer-crash-when-switching-level-editor-viewport-type-to-cinematic-viewport/2747407 POST BODY:Summary The editor crashes when Media Viewer ...

Hot Reloading from IDE fails

UE - Foundation - Core - Jul 13, 2016

Building from VS causes the compilation to fail. (Have not had the opportunity to check XCode yet, investigating) Found in //UE4/Dev-Core @ 3048370 Currently occurs in //UE4/Main @ 3049508Severity ...