check(bRenderStateCreated) fires in SendRenderDynamicData_Concurrent called from FRegisterComponentContext::Process

UE - Rendering - Architecture - RHI - May 18, 2026

FRegisterComponentContext::Process() in ActorComponent.cpp iterates over SendRenderDynamicDataPrimitives and calls SendRenderDynamicData_Concurrent() on each. The existing guard checks ::IsValid(Pri ...

When welding collision between Third Person UE4 Mannequin's left foot ball, to left foot in physics tab results in an Engine crash.

UE - Simulation - Physics - Jan 30, 2019

When using a Third Person UE4 Mannequin, Opening the Physics asset tab, and welding the collision between left foot ball, to left foot results in an Engine crash. Additional Note: Using the same ...

Directly opening a modified map asset of a streaming sublevel does not always force it to be reloaded (inconsistent with other map open behaviors)

UE - World Creation - Worldbuilding Tools - Feb 10, 2026

When the level currently being edited has unsaved changes and the user opens a new one, the Editor asks if the changes should be saved. If the user answers negatively, the level asset is reverted to ...

Blueprint CDO contains removed component from parent class

UE - Gameplay - Blueprint - Apr 28, 2015

Blueprint CDO contains removed component from parent class. From the AnswerHub post: "It appears that if a component is removed from the C++ class, the CDOs for all of the blueprints remain unchang ...

[CrashReport] UE4Editor-MetalRHI.dylib!FMetalDeviceContext::CreateDeviceContext()

UE - Graphics Features - Feb 10, 2017

Error message: SEGV_MAPERR at 0x3 Source Context: Most recent user affected CL: 3249277 Logs: [Link Removed] [Link Removed] [Link Removed] [Link Removed] CrashReporter User Descriptions:Just i ...

Physics Substepping doesn't have the same effect from 4.15 to 4.16

OLD - Anim - Aug 8, 2017

Physics Substepping doesn't have the same effect from 4.15 to 4.16. In 4.16+ the ponytail in the provided project will have a jitter effect even with substepping enabled. This is a regression: Work ...

[CrashReport] UE4Editor_UMG!TBaseDelegate<FMargin>::operator=() [delegatesignatureimpl.inl:381]

UE - Editor - UI Systems - Aug 29, 2017

This is a longstanding and common UMG crash that has affected more than 200 users since at least the 4.15 release. User DescriptionsI was working in the UI and undid several last changes in quick s ...

[CrashReport] UE4Editor_UnrealEd!FBlueprintCompileReinstancer::ReplaceInstancesOfClass_Inner() [kismetreinstanceutilities.cpp:1880]

UE - Gameplay - Blueprint Compiler - Oct 5, 2017

This is a somewhat common crash that has occurred throughout the 4.17 release. Users have not provided any description of their actions when the crash occurred. The callstack is similar to some ol ...

PakFiles: Unmounting PakFile while requests are still in progress causes assertion failure in UnMount

UE - Foundation - Mar 31, 2022

[Link Removed] Licensee is using the chunk downloader. On Shutdown method of their GameInstance, they call FChunkDownloader->Finalize. When they quit the game (Alt+F4) during a chunck download an a ...

Dragging a BP variable into a category can produce inconsistent results

UE - Gameplay - Blueprint Editor - Jan 18, 2019

The drag-onto-category operation is assigning the prettified category name, not the actual category name, resulting in variables that are not actually in the same category, even though they appear t ...