Unreal Engine Issues
Unreal Engine Issues
Unfocused Standalone window has reduced performance
UE - Rendering Architecture - RHI - Aug 25, 2020User description: When I run two windowed standalone instances to test multiplayer, the unfocused window gets about 2-5 fps...but if I focus on it, smooth 120fps, yet the opposite screen is now onl ...
Crash when a subsystem calls GetSubsystemArray() on its owner while engine code is iterating on subsystems also obtained through GetSubsystemArray()
UE - Gameplay - Aug 6, 2024In some occasions, engine code iterates over a certain subsystem type by calling FSubsystemCollection::GetSubsystemArray() and then calling some method on all subsystems of the returned array. This ...
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 ...
Crash when pressing Ctrl-Z after creating a blueprint function
UE - Gameplay - Blueprint - Feb 20, 2017Crash when pressing Ctrl-Z after creating a blueprint function *This is a regression: Working in 4.14.3-3249277 Not working in 4.15.0-3299760* Crash Reporter: Error message: Access violation ...
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 ...
"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 ...
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 - Workflow 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 ...
Editor crashes when BP spline component is selected
Tools - Jan 12, 2017When a spline component point is selected, attempting to select another spline component will cause the editor to crash. Crash also occurs if the same component is selected. Workaround: If the emp ...