Using the BuildGraph to create an installed binary build of the Engine will fail if Simplygon is not installed.

UE - Foundation - Horde - BuildGraph - Oct 13, 2016

A user reported that attempting to create an installed binary build of the Engine using BuildGraph will fail. This seems to be because we include the UE Simplygon implementation, but do not disable ...

UnkownRef Mips can cause TextureStreaming peaks during loading

UE - Graphics Features - Mar 27, 2023

UnkownRef Mips is meant to fix/workaround the problem where some textures are used for rendering but they don't have any component references them (such as texture used by PP effects) These UnkownR ...

"Literal Enum" BP node outputs wrong value when the input pin is connected

UE - Framework - Blueprint - May 17, 2024

This behavior was not observed up to UE 4.19, but it can be reproduced in all versions from 4.20 to 5.4. When a "Literal Enum" node is used inside a blueprint and an enumeration value is chosen fro ...

[CrashReport] UE4Editor_PropertyEditor!SDetailSingleItemRow::OnArrayDrop() [sdetailsingleitemrow.cpp:172]

Tools - Oct 10, 2017

This is a trending crash coming out of the 4.18 previews. Users have not provided any descriptions of their actions when the crash occurred. The callstack shares similarities to [Link Removed] whi ...

iOS Show External Login UI Blueprint Node fails on new iOS devices

UE - Online - Jun 6, 2019

I have been trying to test iOS online subsystem functionality for my game and thought that this blueprint node was just broken. This bug will probably catch many UE4 developers that are new to iOS b ...

BlendSpace DeltaTimeRecord.Delta can incorrectly be set to zero

UE - Anim - Runtime - Apr 19, 2024

It's possible for blendspaces to end up with an invalid delta time record because of how UBlendSpace::TickAssetPlayer modifies the time record.  This only seems to happen with specific settings:Axis ...

Tick functions are skipped on the first frame in package build and standalone PIE

UE - Gameplay - May 19, 2025

It's reported that all Tick functions are skipped on the first frame when running in packaged builds and standalone PIE. This is because both TickVisitedGFrameCounter and GFrameCounter are initializ ...

Crash when opening a blueprint that referenced a struct blueprint that no longer exists

UE - Gameplay - Blueprint - May 28, 2015

If a user creates a struct blueprint then references it in another blueprint and then deletes the struct while the editor is closed, the referencing blueprint will crash when opened. ...

[CrashReport] UE4Editor-D3D11RHI!static void TerminateOnDeviceRemoved(HRESULT, struct ID3D11Device *) [D3D11Util.cpp:160]

UE - Rendering Architecture - RHI - May 6, 2020

This ticket tracks instances of D3DHung crashes now that Aftermath has been enabled in 4.25.0. [Link Removed] was marked fixed and closed with the enabling of Aftermath. Error Messages: Fatal err ...

Cook Determinism - Construction Scripts and ChildActorComponent issues with DiffCooks

UE - Framework - Components - Jul 26, 2024

To step through the issue, in the -DiffOnly cook add a breakpoint to UChildActorComponent::OnRegister and UChildActorComponent::OnUnregister. It should hit 4 times:Once when LoadPackage loads the ma ...