Unreal Engine Issues
Unreal Engine Issues
FKeyHandle internal static atomic counter can overflow on long running games depending on usage pattern
UE - Runtime - Animation - Sep 24, 2025Structure FKeyHandle stores an internal index, which is initialized from a static atomic counter in the default constructor: +----- FKeyHandle::FKeyHandle() { | static std::atomic<uint32> LastKey ...
Memory leak when using Blueprint Debugger while inspecting a return value
UE - Gameplay - Blueprint - Mar 11, 2022Potential memory leak when using Blueprint Debugger to inspect a return value multiple times while playing. User also reported this would cause a crash, but I didn't try to max out ram usage to trig ...
check(bRenderStateCreated) fires in SendRenderDynamicData_Concurrent called from FRegisterComponentContext::Process
UE - Rendering - Architecture - RHI - May 18, 2026FRegisterComponentContext::Process() in ActorComponent.cpp iterates over SendRenderDynamicDataPrimitives and calls SendRenderDynamicData_Concurrent() on each. The existing guard checks ::IsValid(Pri ...
Unreal Engine Fails to Launch with Vulkan SM6 RHI and RenderDoc Auto-Attach Enabled
UE - Rendering - Architecture - RHI - Dec 3, 2025When launching Unreal Engine with the Vulkan RHI, SM6 and RenderDoc Auto Attach on Startup enabled, the engine fails to initialize with the error: “A compatible Vulkan Driver is required to run the ...
Editor Utility Widgets: Asset creating nodes' output pins in uber graphs cause asset deletion warning
zComponent - Archive - Oct 8, 2024Editor Utility Widgets (EUW) can be used to script editor behavior. One use case is the automation of asset creation. A licensee has reported that when an EUW is used to create an asset, for as lon ...
[CrashReport] Assertion on in UMaterialInterface::InitDefaultMaterials()
UE - Graphics Features - Jun 28, 2017This is a common Mac crash occurring in the 4.16.1 release. I have not found any evidence of it occurring on Windows. The callstack closely matches [Link Removed], which was briefly experienced by ...
Users can create project with name of "Stack" which causes conflict with existing "Stack.h"
Tools - Sep 12, 2016Users can create project with existing name of "Slack" which causes conflict with existing Slack.h. Call stack is log file. ...
Warnings Log spam when pasting a widget into any panel widget
UE - Editor - UI Systems - Jun 8, 2018An increasing amount of warning show up in the output log as a widget is pasted into a name space that is part of a widget that has been added to another widget via the user created section. Examp ...
ImportAssets commandlet failing to create assets in project
UE - Editor - Content Pipeline - Import and Export - Mar 14, 2017There are no errors or warnings in the console output or logs that suggest anything went wrong. Also attempted to import a .PNG with no luck. Exact command used, use of <user> where appropriate:UE4 ...
Slate Widget fails to compile once added to a new project
UE - Foundation - Core - Jan 28, 2015Slate Widget fails to compile when you add it to a new project. Expected as a user that anything in that default list should be able to be added and compile fine without making any changes. Compil ...