Unreal Engine Issues
Unreal Engine Issues
StateTree: While editing State Parameters or exposed properties of a Condition/Task, an ensure() fires when editing inputs of a Property Function bound to an array element
UE - AI - StateTree - Mar 5, 2026Consider an array property that can be edited in the StateTree editor. This can be a State Parameter or an exposed property of a Condition or Task, for example. Each element of the array can be boun ...
Wrong WPO motion vectors due to Periodic World Space node
UE - Rendering - Graphics Features - May 13, 2026We've noticed smearing in grass due to wrong motion vectors. This appears to be caused by lack of previous frame support in the periodic world space node. This is how we fixed it: In MaterialTempl ...
Virtual Memory leak when using specific rendering settings in the template project
UE - Rendering - Architecture - RHI - Dec 20, 2025When a project is run with these settings in a template project, untracked virtual memory increases. Cvars r.GBufferFormat 3 r.Lumen.TraceMeshSDFs 1 r.Lumen.TranslucencyReflections.FrontLayer.Enab ...
[CrashReport] UE4Editor_CoreUObject!UObjectPropertyBase::Identical() [propertybaseobject.cpp:60]
UE - Foundation - Cpp Tools - Hot Reload - Nov 17, 2016This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Error message: Access violation - code c0000005 (first/second chance not available) Source C ...
User-defined InstancedStaticMeshComponent subclass misbehave in SCS Editor
UE - Framework - Blueprint Editor - Oct 13, 2025Context Users can create InstancedStaticMeshComponent (ISMC) (blueprint) subclasses. Any ISMC class can be added to an actor blueprint. When a mesh is selected and transforms are added to the Insta ...
Backwards-compatibility broken for the CDOs of Python-generated Unreal Types because of missing redirectors
UE - Editor - Feb 11, 2025Previously, all Unreal Types generated by python scripts would be created inside package "/Engine/PythonTypes". This was changed by [CL 32478991 in ue5-main branch], which meant to "remove the restr ...
[CrashReport] Crash on Mac - UE4Editor-SlateCore.dylib!SWindow::IsVisible()
UE - Platform - Apple - Jun 23, 2017This is a common crash on Mac in the 4.16 release, and has occurred with low frequency since at least 4.11. Users have not provided any descriptions, so additional information is currently unknown. ...
iOS fails during build step with OSS Facebook plugin enabled due to spaces in filepath
UE - Platform - Mobile - Feb 8, 2019When a user tries to package or launch onto an iOS device they will fail at the build step due to:[3/8] sh Unzipping: /Users/Shared/Epic Games/UE_4.22/Engine/Source/ThirdParty/Facebook/IOS/FacebookS ...
Multiplayer Shootout project sample is crashing on start
Docs - Samples - Apr 3, 2015The project sample Multiplayer Shootout in the Learn tab is crashing on start up with 4.7.4 Crash does not occur on 4.8. Tested by Patrick.D on Main CL-2498147 Pass in 4.7.5 dev. - CKC 2503383 ...
"FVector contains NaN" on packaged builds for Debug configuration
UE - Graphics Features - Lumen - May 6, 2022Customer Provided Description:This was experienced in UE 5.01 - custom installed engine (No changes to UE code, simply added the Debug build configuration, see the following command): "c:%ue_dire ...