Simulated ability tasks not being cleaned up in UActorChannel::ReplicationMap

UE - Networking - Nov 20, 2018

I've noticed the issue occurring in both 4.20.3 (CL 4369336) and 4.21.0 (CL 4541578). The user on AnswerHub has also noticed the issue in 4.20.2 (CL unknown) and claims the issue did not occur in 4. ...

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 ...

BuildPatchTool crashes on Mac and Linux when building android or ios with multiple chunks

Portal - Feb 18, 2020

"It seems that deallocation of TLazySingleton<FInternationalization> causes unhandled exception. If DISABLE_LAZY_SINGLETON_DESTRUCTION=1 is provided - the build completes successfully" ...

[CrashReport] UE4Editor_Slate!FSlateApplication::RoutePointerMoveEvent() [slateapplication.cpp:5195]

UE - Editor - UI Systems - Slate - Jun 28, 2017

This is a longstanding crash that occurs with low frequency, but has affected over 200 users. One user describes that this occurred while packaging a project, although other users have not provided ...

Capsule Shadows Not Visible When Using Movable Skylight With Bright Lower Hemisphere Color and Indirect Lighting Cache

UE - Graphics Features - May 9, 2018

I have managed to reproduce this issue in 4.18.3 and 4.19.2. In order to make the Capsule Shadow disappear:Indirect Lighting Cache must be used (Volumetric Lightmap works)Skylight must be set to 'M ...

Packaging to HTML5 fails when Online Framework is enabled

UE - Online - Nov 17, 2018

Packaging a project to HTML5 while Online Framework is enabled seems to cause packaging failures. It produces the following errors from the Output Log:   PackagingResults: Error: unresolved symbol: ...

[CrashReport] UE4Editor_Persona!<lambda_e529d88d0657fbede17be1535bc6d479>::operator() [blendspacedetails.cpp:29]

OLD - Anim - Aug 14, 2017

This is a trending crash coming out of the 4.17 release. Users have not provided any descriptions of their actions when the crash occurred. The callstack is very close to https://jira.it.epicgames ...