Unreal Engine Issues
Unreal Engine Issues
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 - Workflow Systems - 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 ...
[CrashReport] UE4Editor_CoreUObject!StaticAllocateObject() [uobjectglobals.cpp:2153]
UE - Anim - Sequencer - Jun 3, 2016Really close to the repro steps for [Link Removed] Same repro steps produced the following Buggs along with this one: [Link Removed] [Link Removed] Error message: Fatal error: [Link Removed] [Lin ...
LoadErrors:Warning: Warning CreateExport: Failed to load Outer for resource when moving Blueprints folder to another folder
UE - Gameplay - Blueprint - Apr 14, 2017There are 3 assets from Content > Blueprints > Missing Types that are failing to be moved over The assets are causing the warnings are:BP_NodeClassIsMissingBP_ParentClassIsMissingTypeBP_PinReferenc ...
Actors disappearing after saving a large number of modifications to world partition maps
UE - Editor - Workflow Systems - Nov 4, 2022From Licensee: "We've encountered a world partition bug where newly created actors go missing in the viewport and Outliner after saving modifications to a large number of actors. This bug is partic ...
Ensure triggered inside Range Struct Customization when Property Node is no longer valid (e.g. when editing FFloatRange while FRuntimeFloatCurve editor is visible) [Ref. UE-341339]
UE - Editor - UI Systems - Nov 12, 2025[Link Removed] was fixed by CL 46990575, successfully avoiding an ensure condition inside FIntervalStructCustomization::SetValue() when its Property Node is no longer valid. However, the same proble ...