Crash When Loading Cooked Material Assets in Editor Due to Shader Serialization

UE - Rendering Architecture - Shaders - Aug 27, 2025

In Unreal Engine 5.6+, the new shader serialization logic in FShaderMapResourceCode::Serialize does not correctly handle cooked assets that are loaded back into the editor (e.g., from a mounted .pak ...

[CrashReport] Assertion on Mac: Could not create a libwebsocket - FNetworkFileServerHttp::Init()

UE - Platform - Mobile - Jun 22, 2017

This is a common crash on Mac that occurs in the 4.16 release. This appears similar to [Link Removed], which was closed with the 4.13 release. Users have not provided descriptions. Many (but not a ...

Cannot select child anim BPs for use in linked anim layers

UE - Anim - Runtime - Jul 15, 2021

From UDN: [Link Removed] Unable to set a Child ABP with inherited interface to a Linked Animation Layer Instance Class. I have a ABP_Biped which is our main ABP. I have the locomotion (idle+straf ...

AbilityTask_PlayMontage will 'zombie' if Interrupted during BlendOut

UE - Gameplay - Gameplay Ability System - Apr 14, 2023

User reports: I've noticed a bug with PlayMontageAndWait There are 4 possible triggers when a Montage completes:OnCompletedOnBlendOutOnInterruptedOnCancelled Once OnBlendout has been triggere ...

Gauntlet test warnings in QAGame Win64 Development BootTest

UE - Rendering Architecture - RHI - Sep 6, 2023

QAGame Win64 Development BootTest: * Ensure: Ensure condition failed: oldValue == newValue [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Private\HAL\ThreadingBase.cpp] [Line: 311] oldVal ...

Non-existing config file loading could cause memory leak

UE - CoreTech - Oct 19, 2023

The cause of this problem is the Engine has code paths which register a new allocated object to Map without deleting the previous object. In the repro project, whenever hitting Space Bar, the level ...

[CrashReport] UE4Editor_Core!FArchiveFileReaderGeneric::InternalPrecache() [filemanagergeneric.cpp:697]

UE - Foundation - Core - Jun 20, 2016

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Assertion failed: false [Link Remo ...

ENGINE: CRASH: One off Editor Crash with ANavLinkProxy::GetComponentsBoundingBox() navlinkproxy.cpp:189

UE - AI - Oct 20, 2016

One off editor crash. [Link Removed] Error Message Access violation - code c0000005 (first/second chance not available) Call Stack of Most Recent Crash ANavLinkProxy::GetComponentsBoundingBox() na ...

Once an actor channel is closed by NetCullDistance, root motion movement synchronization stops working

UE - Networking - Jul 12, 2021

Properties that uses DOREPLIFETIME_ACTIVE_OVERRIDE (ex. RepRootMotion ) will also skip replication when an actor channel is newly opened. This means that if the variables on the server side do not c ...

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

UE - World Creation - Worldbuilding Tools - 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 ...