Map placed actor binding to another actor's Event Dispatcher (multicast delegate) results in duplicate bindings after blueprint recompile

UE - Framework - Blueprint - Apr 17, 2025

Context Blueprint actors placed on the map can bind to another actor's event. If an ActorB has a reference to ActorA, it can bind to an event dispatcher in A by creating an event node in ActorB's e ...

ARSharedWorld, AREnvProbe, and ARSaveLoad fail to build for iOS with clang error

UE - Platform - Mobile - Jul 18, 2019

ARSharedWorld fails to package at the build command for iOS with the following messages. Packaging (iOS): [1/4] sh /Volumes/Storage/Workspaces/Release/Samples/AR/ARSharedWorld4.23/Binaries/IOS/ARS ...

~FStaticMesh() can crash with race condition

UE - Graphics Features - Mar 21, 2017

UDN user reported frequent crashes in FStaticMesh::~FStaticMesh() on DrawListLinks[i]->Remove(false); Crash went away after adding critical sections to FStaticMesh::LinkDrawList(), FStaticMesh::Unl ...

Mutable references MetaHumans heads directly, but DNA Assets are private

UE - Anim - Mutable - Sep 18, 2025

When we switched our project to 5.6.1 This error appeared on build. The compilation of the Mutable assets in the editor is not reporting any issue. ...

CRASH: Random Crashes: Access violation - code c0000005

UE - Gameplay - Blueprint - Dec 30, 2014

Crash Report: [Link Removed] UE4Editor_CoreUObject! UPackage::SavePackage() + 23952 bytes savepackage.cpp:3305 UE4Editor_UnrealEd! UEditorEngine::SavePackage() + 1065 bytes editor.cpp:4368 UE4Edi ...

The process may not return to the root node after the Wait Task is completed.

UE - AI - BehaviorTree - Sep 14, 2021

If the Wait Task is completed for the first frame, it may not return to the root node even after Finish. This can be avoided by increasing the wait time of the Wait Task (see CaseOK.mp4). When this ...

[CrashReport] Assertion on Mac in FCocoaRunLoopSource

UE - Platform - Apple - Jun 14, 2017

This is a common crash among Mac users in 4.16. It is spread out among many separate CrashGroups, with slight variations in Callstack. Some Example CrashGroups [Link Removed] [Link Removed] [Link ...

Compile error during build stage when packaging for tvOS

UE - Platform - Mobile - Dec 9, 2016

Compile error packaging for tvOS: Does not affect iOSUATHelper: Packaging (tvOS): UnrealBuildTool: D:\Build\joseph.wysosky_Main\Engine\Source\Runtime\Core\Private\iOS\IOSAppDelegate.cpp(388,12): ...

[CrashReport] UE4Editor-MetalShaderFormat.dylib!FGenerateMetalVisitor::print_constant()

UE - Graphics Features - Sep 22, 2017

This is an early trending crash coming out of the 4.18 previews. It occurs on Mac, and all affected project names indicate it is related to AR. Users have not provided any descriptions of their ac ...

[CrashReport] Linux crash - FScopeContext::FScopeContext()

UE - Platform - Linux - Oct 5, 2017

This is a somewhat common Linux crash occurring in 4.17.2. (there are a few older records in 4.16.2 and 4.17.1 also, but most occur in 4.17.2) Callstack from Log[2017.10.04-14.49.42:768][ 2]LogFi ...