Unreal Header Tool can sometimes fail if an Engine plugin is Enabled By Default and has the "Program" Module Type set

UE - Foundation - Core - Feb 15, 2018

An Engine plugin with the Program module type and EnabledByDefault set to true can cause the Engine to fail to build successfully due to UHT failing. I was only able to reproduce this behavior using ...

Gameplay Tags with the string "None" as any of its hierarchical node identifiers behave incorrectly (because of an incomplete generated FGameplayTagContainer::ParentTags array)

UE - Gameplay - Nov 19, 2024

Currently, using the string "None" as a hierarchical node identifier inside a Gameplay Tag (for example "A.B.C.None.D.E.F") is not disallowed by the engine, but results in some incorrect behaviors. ...

Changing the state of a PrimitiveComponent->BodyInstance while SetSimulatePhysics(false) updates the game thread but does not update the physics behavior

UE - Simulation - Physics - Nov 21, 2024

Changing the state of a PrimitiveComponent->BodyInstance while SetSimulatePhysics(false) updates the game thread but does not update the physics behavior. In the repro project provided (see addl in ...

Shortcuts do not appear to work for the visual logger

UE - AI - Nov 16, 2017

Shortcuts do not appear to work for the visual logger in the editor preferences ...

Crash when toggling the SmartLinkEnabled state of a NavLinkProxy specifically in a packaged game targeting Debug/Development

UE - AI - Navigation - Jan 24, 2025

The licensee has reported, and I was able to reproduce, that specifically in package builds targeting Development configuration, trying to toggle the SmartLinkEnabled state of a NavLinkProxy will cr ...

Visible dithered quantization to remove banding in New Temporal AA Quality

UE - Graphics Features - Oct 6, 2015

Since changing the temporal history buffer to 11:11:10 from FP16, it looks as there is visible dithered quantization to remove banding when rendering. (Taken from conversation on Forum Post linked f ...

Physics Constraint returns incorrect values for Swing1, Swing2, and Twist

UE - Simulation - Physics - Jul 7, 2022

Tested in //UE5/Main CL#20966071 Tested in //UE4/Release-4.27 CL#18319896 Physics Constraint returns incorrect values for Swing1, Swing2, and Twist. ...

Delta struct serialized fast arrays replicating new elements with no changelist

UE - Networking - Jun 14, 2021

There is a scenario where delta struct serialized fast arrays can replicate changes that introduce additional elements to the array, but without changelists containing the new data. This needs furt ...

Deploying from Windows to Linux fails on the first attempt

UE - Platform - Linux - Aug 3, 2017

After hitting this failure, if you try to deploy again, then it will work. This only occurs on the first attempt. Initially, I thought I hit a disc space issue I was hitting due to having a sample ...