Client and server can both get stuck waiting for packet sequence history flush

UE - Networking - Sep 4, 2025

The issue occurs when both instances have a significant difference between their last sent and last ack'd sequence number, as they will begin waiting for the sequence history to be flushed for a pac ...

Sequencer is not taking into account the TransformOriginOffset of the level sequence actor.

UE - Anim - Sequencer - Sep 3, 2025

When a level sequence actor has camera's marked for preroll in it and information is gathered for a camera cuts location to send to the streaming manager, it does not take into account the Transform ...

When ControlRig.EnableAnimNodePerformanceOptimizations is enabled, the default pose briefly appears after the Control Rig is reinitialized

UE - Anim - Rigging - Control Rig - Sep 1, 2025

Since UE5.6, ControlRig.EnableAnimNodePerformanceOptimizations is enabled by default, and this appears to be causing the issue. Specifically, when the control rig’s construction event is processed, ...

Crash when running "MAP REBUILD ALLVISIBLE" with hidden sublevels and then changing maps

UE - World Creation - Worldbuilding Tools - Sep 1, 2025

Running the MAP REBUILD ALLVISIBLE editor command when the current map contains hidden sublevels causes a crash upon changing maps. The issue seems to be related to hidden sublevels being cleared in ...

GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues

UE - Simulation - Visual - Aug 30, 2025

GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues. The licensee has provided their analysis: We seem to have stumbled acro ...

Material Particle SubUV Sample does not work with Tex Object

UE - Rendering Architecture - Materials - Aug 29, 2025

The Particle SubUV Sample node uses its own texture object reference instead of the one provided by the texture object node. ...

Crash When Loading Cooked Material Assets in Editor Due to Shader Serialization

UE - Rendering Architecture - Shaders - Aug 27, 2025

In Unreal Engine 5.6+, the new shader serialization logic in FShaderMapResourceCode::Serialize does not correctly handle cooked assets that are loaded back into the editor (e.g., from a mounted .pak ...

StateTree : Crash when executing GetPropertyRef in SubTree linked via Linked Asset

UE - AI - StateTree - Aug 26, 2025

A crash occurs when GetPropertyRef node is executed from a SubTree that is linked within a StateTree, which itself has been linked from a parent StateTree via a Linked Asset ** . The processing con ...

BP Debugger: Unable to inspect debug data for ForEachLoop ArrayElement, Array_Get and Break Struct output pins

UE - Framework - Blueprint - Aug 26, 2025

Context The blueprint debugger allows you to trigger breakpoints and inspect the current state of variables, both member variables, local variables and persistent UberGraph variables. Problem The ...

"Detaching from existing linker" error messages when running Fixup Redirectors commandlet

UE - World Creation - Worldbuilding Tools - OFPA - Aug 25, 2025