Vector VM - Crash / memory stomp when using > 255 external function calls

UE - Niagara - Aug 12, 2025

The Vector VM has only every supported a byte's worth of external function calls, when we blew the limit it would index into the incorrect VM call. The new VM will also overwrite memory when exceed ...

Modifying PostProcess Film Slope can cause TSR to produce ghosting artefacts

UE - Graphics Features - Aug 11, 2025

When TSR is active, the scene is dark, and a foreground object is lit, modifying the Film/Slope value on a PostProcessVolume can lead to TSR ghosting. TSR occurs prior to Tonemapping, so the issue ...

Rewind debugger would crash when recording a character using Pose search

UE - Anim - Gameplay - Aug 8, 2025

Our character is using the Pose search setup from GameAnimation content example. The architecture of the system is most the same with some new function that account for some input difference and sp ...

Using ForceCustom Mode causes TPose for single frame in Level Sequencer

UE - Anim - Sequencer - Aug 8, 2025

We are seeing TPose issues when swapping between EDL shots on skeletal mesh actors. We have spawned skeletal mesh actors added to a Level sequence that are set to use an animation blue prints which ...

GPU Crash from out of memory read/writes in Lumen when using non-power-of-2 TracingOctahedronResolution

UE - Graphics Features - Lumen - Aug 6, 2025

When the r.Lumen.ScreenProbeGather.TracingOctahedronResolution is not a power of 2 or LumenFinalGatherQuality in a Post Processing Volume is set to a value such that the TracingOctahedronResolution ...

Iris - RPCs split into partial blobs aren't received on non-replicated components

UE - Networking - Iris - Aug 5, 2025

This issue does not occur if the RPC is not split into partial blobs. The RPC is received on the non-replicated component if Iris is disabled. ...

FInstancedStruct does not serialise to JSON when used in a DataTable

UE - Editor - Workflow Systems - Aug 4, 2025

The JSON export functionality for DataTable relies on a FieldIterator to gather properties. This iterator is unable to gather the properties from the InstancedStruct. CSV export functionality works ...

Sequence thumbnails save with visual issues

UE - Anim - Sequencer - Aug 1, 2025

[Link Removed] When camera tracks are activated, saving the sequencer results in captured anomalies: 1. Incorrect aspect ratio 2. Additional post-processing effects such as lens flare appear 3. ...

Add dll-exposure to landscape patch public functions that are meant to be used by external modules

UE - Graphics Tools - Terrain - Landscape - Jul 31, 2025

ULandscapePatchComponent::SetIsEnabled, IsEnabled, etc. are all callable from BP but not from c++. This is not convenient for licensees ...

ULocalPlayerSaveGame::IsSaveInProgress always returns true after a save completes

UE - Framework - Jul 31, 2025

ULocalPlayerSaveGame::IsSaveInProgress always returns true after the first save is requested. This is due to the return statement checking if either an error has yet to be reported or a success has ...