Second controller input doesn't work setting client mode on PIE.

UE - Gameplay - Input - Feb 3, 2021

When two controllers connected, player2 input is disabled in client mode in PIE. It worked correctly in 4.25, but it has been wrong since 4.26.  Digging into FSlateApplication::ProcessKeyDownEve ...

Unable to play replays with custom GameNetworkProtocolVersion set at runtime

UE - Networking - Sep 20, 2023

It seems that when comparing the custom versions for a replay (in the "operator<<" defined in ReplayTypes.cpp), the value retrieved from the FCurrentCustomVersions is not the value set at runtime, b ...

Logging out and then logging in as a new user results in slate creating multiple Slate User IDs

UE - Gameplay - Input - Jul 28, 2023

I believe this is happening because when you change your logged in user, the Slate Application will automatically create a new second slate user with an ID of 2. This is bad because the Slate App is ...

Iris - Server fails to send client initialization RPCs after seamless travel if the client finishes travelling first

UE - Networking - Iris - Nov 18, 2025

During seamless travel, when a client loads into the destination level it will call APlayerController::ServerNotifyLoadedWorld, including when it finishes the travel before the server. When the serv ...

Does FSlateElementBatcher::AddCachedElements need to check if r.HDR.UI.CompositeMode is enabled?

UE - Editor - UI Systems - Aug 28, 2024

When a specific configuration of HDR cvars are set, PIE in a New Editor Window will not render the game world. Settings (For DefaultEngine.ini): ```[SystemSettings] r.AllowHDR=1 r.HDR.Display.Color ...

Controller Mapping/Unmapping on some platforms is not ideal for local multiplayer

UE - Gameplay - Input - Nov 19, 2025

[Link Removed] The workaround is as I posted in the UDN, to override the viewport client or to make a custom slate input mapping to change this behavior. But, there is a bug with that unmapping/l ...

[AI] WP Dynamic navmesh fails to rebuild tiles with actors that are loaded but not part of the base navmesh.

UE - AI - Navigation - Feb 18, 2025

WP dynamic navmesh does not properly react to actors or navigation modifiers that are loaded in areas that the navmesh has not yet streamed into. Although the actors/modifiers are not part of the ba ...

In the level editor, when configuring a component that is part of an actor blueprint, adding entries to a TMap with C++ enum keys results in duplicate keys and an incorrect warning popup.

UE - Editor - Workflow Systems - Jan 22, 2026

Note: This started happening in UE 5.4 and persists up to latest. It is probably related to [Link Removed] Closed ([Link Re ...

UNetDriver server-side hitch results in ActorInfo->NextUpdateTime far into future

UE - Networking - Feb 16, 2024

A high UWorld::Tick DeltaSeconds (i.e. GameThread hitch) results in a high UNetDriver::TickFlush DeltaSeconds. This DeltaSeconds can high (many seconds) if the hitch is long. This value then affects ...

The Remove-On-Break feature, set on Fracture Mode on Geometry Collections, stops shrinking and shows strange behaviors

UE - Simulation - Visual - Oct 15, 2024

The Remove-On-Break (ROB) feature, set on Fracture Mode on Geometry Collections (GC), was supposed to make the particle shrink until it vanishes. When the GC goes to sleep the shrinking stops and sh ...