Unreal Engine Issues
Unreal Engine Issues
Crash When Loading Cooked Material Assets in Editor Due to Shader Serialization
UE - Rendering - Architecture - Shaders - Aug 27, 2025In 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 ...
Open Formats: glTF Import - importer truncates skeletal mesh bone influences to 4 per vertex
UE - VEI - Open File Formats - Aug 21, 2026cf https://forums.unrealengine.com/t/interchange-gltf-importer-truncates-skeletal-mesh-bone-influences-to-4-per-vertex/2745391/2 Original message The UE5 Interchange GLTF importer appears to trunc ...
[CrashReport] Assertion on Mac: Could not create a libwebsocket - FNetworkFileServerHttp::Init()
UE - Platform - Mobile - Jun 22, 2017This 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 - Runtime - Animation - Jul 15, 2021From 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, 2023User 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 - RHI - Sep 6, 2023QAGame 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 - Core - Systems - Oct 19, 2023The 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 ...
Regarding TObjectPtr performance regression
UE - Core - Systems - Jul 13, 2026This is from the linked EPS case: ============================== When 5.0 first introduced TObjectPtr, the guidance was that it would compile down to raw pointer access in Shipping builds to ensu ...
Chaos Trailing Events not exposed to Blueprints and only accessible via Niagara Chaos DI
UE - Runtime - Deformable - Apr 22, 2025Chaos Trailing Events not exposed to Blueprints and only accessible via Niagara Chaos DI. The licensee noticed that the Trailing event is not available to BPs. It's expected that the same data avail ...
[CrashReport] UE4Editor_Core!FArchiveFileReaderGeneric::InternalPrecache() [filemanagergeneric.cpp:697]
UE - Foundation - Core - Jun 20, 2016This 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 ...