Unreal Engine Issues
Unreal Engine Issues
MovieSceneAnimMixer: Force Root Lock suppression is editor-only, causing PIE vs cooked divergence
UE - Anim - Sequencer - Jul 13, 2026The anim mixer's skeletal animation eval task suppresses an anim sequence's Force Root Lock during pose evaluation so the root-motion extraction task (FAnimNextExtractRootMotionTask) can measure and ...
AdditionalPluginDirectories when set are not reflected in generated projects
UE - Core - Cpp Tools - UnrealBuildTool - Jan 3, 2023Bug report viaUDN: We have some plugins that we'd like to share between projects, that we don't want to maintain multiple copies of. The AdditionalPluginsDirectories option for Project's solves tha ...
Out-of-bounds read caused by improper return size from FSocketSteam::RecvFrom in Unreal Engine
UE - Online - Jun 7, 2021Overview: Function at fault: FSocketSteam::RecvFrom (https://github.com/EpicGames/UnrealEngine/blob/c3caf7b6bf12ae4c8e09b606f10a09776b4d1f38/Engine/Plugins/Online/OnlineSubsystemSteam/Source/Private/ ...
USDStage - Issues importing USD prims with single time-sampled attributes
UE - Editor - Content Pipeline - USD - May 10, 2022There may be an issue with USD prims with time-sampled attributes - or at least an issue of user expectations. When importing from a USDStageActor into Unreal, via the USDStage GUI, if prims hav ...
Editor crashes due to a material that contains MPCs migrated from another project
UE - Rendering - Architecture - Materials - Apr 29, 2024[2024.04.29-16.49.46:563][970]LogUObjectGlobals: Warning: LoadPackage can't find package /BEURRE_040824_041224/NewMaterialParameterCollection. [2024.04.29-16.49.46:563][970]LogUObjectGlobals: Warning ...
UAssetManager::ChangeBundleStateForPrimaryAssets: Performance: Avoid canceling loads in progress when new bundles added and the in progress bundles are kept
UE - Core - Data Pipeline - Cooker - Mar 4, 2024UAssetManager::ChangeBundleStateForPrimaryAssets allows adding new BundleNames to the list of BundleNames loaded for a PrimaryAssetId. Each BundleName specifies a BundleEntry with a list of assets. ...
Crash in GC - FSharedStruct reachability race condition
UE - Core - Systems - Jul 13, 2026This Jira was created from the linked EPS case: =============================================== This issue is caused by FSharedStruct batching reachability requests to the same underlying FInstan ...
[CrashReport] UE4Editor_Engine!FUniformExpressionSet::CreateUniformBuffer() [materialuniformexpressions.cpp:354]
UE - Graphics Features - Nov 30, 2015Error Message - Assertion failed: !Value || Value->IsValidLowLevel() [File[Image Removed]:\BuildFarm\buildmachine_++depot+UE4-Releases+4.10\Engine\Source\Runtime\Engine\Private\Materials\MaterialU ...
Crash on attempt to clear(NullifyInstance) of duplicated Hierachial Instanced Static Mesh
Tools - May 31, 2019When creating an C++ Actor with a Hierarchical Instanced Static mesh. when duplicating such an actor with mesh instances, the instances are not visible on the level. In this state, calling HISM comp ...
Classes in TargetDenyList modules are still referenced from Components on BlueprintGeneratedClasses and cause runtime warnings
UE - Core - Systems - Feb 25, 2024Other than the presence of the error and the performance cost of looking for a package on disk that does not exist, there are no behavioral problems. When running with legacy (non-iostore) pakfiles ...