Division by zero causing NaN/Inf on USkeletalMeshComponent::UpdateRigidBodyScaling() when setting scale to zero and back

UE - Simulation - Core - Feb 11, 2026

Up to UE 5.5, skeletal mesh physics did not get updated when the component's scale changed. This was improved on January 2025 with CL 39190335, which addressed [Link Removed] ...

GPU Timeout when using a large scale Landscape and Water Body Ocean

UE - Graphics Tools - Terrain - Landscape - Dec 1, 2022

Regression: Tested in //UE5/Release-5.0, this issue does not occur so regression is yes. The GPU Timeout only occurs in UE5/Release-5.1, as recreating this issue in previous versions of the editor ...

Inversing the scale of a skeletal mesh when it's simulating physics results in the mesh and collision being flipped

UE - Simulation - Core - Mar 18, 2021

The attached project has 3 skeletal meshes. One with its original transform and then 2 copies with an inversed scale in the X axis for one and the Y axis for the other. When pressing play, the meshe ...

Hardware Raytracing on Lumen can cause a crash on AMD Radeon GPUs

UE - Rendering - Graphics Features - Lumen - Jul 29, 2025

Hardware Raytracing support can cause a crash on AMD Radeon GPUs when creating the RT pipeline state. ...

The Editor "Show Frame Rate and Memory" does not display the intended output on macOS.

UE - Platform - Apple - Jan 11, 2023

Repro Rate: 5/5 This is a live issue that has been tested in the Binary build of //UE5/Release-5.1 at CL 23058290 and DOES NOT OCCUR in Windows and Linux but DOES OCCUR in Mac. This was tested on d ...

FILTER_COMMANDLINE_LOGGING cannot be used without forcing UE_COMMAND_LINE_USES_ALLOW_LIST

UE - CoreTech - Jul 30, 2024

There's two ways to affect the commandline in CommandLine.cpp: FILTER_COMMANDLINE_LOGGING - for filtering certain or all args (if left empty) from the log. UE_COMMAND_LINE_USES_ALLOW_LIST - for on ...

Provided example Control Rig Python scripts that feature calls to GetControlRigBlueprint need to be updated to GetControlRigAssetInterface.

UE - Anim - Rigging - Control Rig - Dec 9, 2025

The unreal.ControlRigContextMenuContext.get_control_rig_blueprint() this function has been deprecated in Unreal Engine 5.7. As a result, the Python scripts included with the Control Rig plugin no ...

Structured log automated decimal number tests fail in languages / cultures that use commas instead of periods

UE - Foundation - Jul 17, 2025

The following Localisation Tests in "Engine\Source\Runtime\Core\Tests\Logging\StructuredLogFormatTest.cpp:275" TestLoc(LOCTEXT("Float", " {Float} "), ANSITEXTVIEW(R"(128.25)")); TestLoc(LOCTEXT ...

Plugin cannot be created when adding the "-" character

UE - Foundation - Cpp Tools - Plugin System - Dec 15, 2022

Repro Rate: 10/10 This issue occurred in the live build of //UE5/Release-5.1 at CL 23058290. This was regression tested against //UE5/Release-5.0 at CL 20979098 and is confirmed to not be a regres ...

FJsonObjectConverter::ExportCallback_WriteISO8601Dates allows for writing FDateTime that does not have ticks

UE - CoreTech - Mar 12, 2025

Context: `FJsonObjectConverter` is a built-in UE class that makes it easy to convert JSON objects to and from UStructs, including `FDateTime`, which implements a date and time. Problem: An uniniti ...