GAS and single process PIE: modifiable static variables accessed by server and client

UE - Gameplay - Gameplay Ability System - Nov 16, 2022

See: UAbilitySystemGlobals::HandlePreLoadMap GAS features static variables that are modified by both server and client, thus result in issues in single process PIE where they access the same memory ...

When duplicating the last point in a closed-loop spline, its metadata is inserted at the wrong index

UE - Editor - Nov 1, 2023

The SplineComponentVisualizer allows users to alt+drag on a spline point to duplicate it. When this is done on the last point of a spline marked as "closed-loop", the new point is correctly added at ...

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 ...

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 ...

[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 ...

Crash when starting PIE on a World Partition level with a Niagara Component inside nested Child Actor Components

UE - Niagara - Jun 25, 2024

Consider an actor containing a Niagara Particle System Component, which is instantiated from another actor's Child Actor Component. When initializing PIE on a World Partition level containing this s ...

Wrong calculation of "MaxAllocatedCountEstimate" inside FNiagaraRendererRibbons::GenerateDynamicData()

UE - Niagara - Mar 20, 2026

Starting with UE 5.4, function FNiagaraRendererRibbons::GenerateDynamicData() from file [NiagaraRendererRibbons.cpp] attempts to calculate DynamicData->MaxAllocatedCountEstimate as such: DynamicDat ...

[CrashReport] Assertion failed: GetOuter()==NULL in UE4Editor_Core!FText::IsEmpty

Tools - Apr 17, 2017

This is a top 10 crash affecting many users. It is believed it may be related to the auto listen / reimport feature. The callstack shares similarities to past tickets, such as:[Link Removed][Link R ...

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 ...