PlayMontages can break after binding an actor with an AnimInstance inside a LevelSeuqence.

UE - Anim - Sequencer - May 28, 2025

When an Animation Sequence is overridden by a LevelSequence, and later reverts to its original animation state, the AnimInstance fails to properly reinitialize. This prevents subsequent animation lo ...

Duplicated PCG Component instance resets overridden parameters to default

UE - Graphics Tools - PCG - Components - Jun 4, 2025

Context: Similar to parameters in the Material editor, PCG Graph Parameters are user created overridable values and can help create customizable graphs for a variety of situations. Problem: The l ...

UWorldPartitionSubsystem::IsStreamingCompleted returning the wrong query result when all cells and actors in location are in DataLayers

UE - Engine Scaling - Streaming - World Partition - Jul 24, 2025

Context: Data Layers is a system within World Partition used to organize Actors both in the Editor and at runtime. It allows for the user to dynamically load and unload layers in the Editor to help ...

Incorrect resolution used because SetProcessDpiAware() is not called when bAllowHighDPIInGameMode=False

UE - Rendering - Architecture - Aug 8, 2025

The incorrect resolution is used on computers with 4k monitors that use DPI scaling (default 150%) because the default for UE projects is bAllowHighDPIInGameMode=False which results in SetProcessDp ...

Interaction between sublevels and LevelSequences can break actors attachments hierarchy of the sublevel.

UE - World Creation - Worldbuilding Tools - Aug 6, 2025

Having a LevelSequence opened and unhiding a sublevel can break the attachment hierarchy of the actors that are inside the sublevel. This also affects to the sublevel asset itself. ...

Niagara Data Interface "Errors and Warning" section on Module Details not updating when error messages change

UE - Niagara - Aug 14, 2025

This is a regression: it worked correctly up to UE 5.5, but not in 5.6 or mainline latest. Possibly caused by CL 40093049. Class UNiagaraDataInterface provides virtual method GetFeedback(), which a ...

Environment Query System (EQS): EnvQuery runtime template object can be created with a non-unique name, corrupting the EnvQueryManager cache

UE - AI - Aug 5, 2025

On file [Engine\Source\Runtime\AIModule\Private\EnvironmentQuery\EnvQueryManager.cpp:812], function UEnvQueryManager::CreateQueryInstance() uses StaticDuplicateObject() to create a new UEnvQuery* (d ...

FXmlFile fails to parse well-formed XML when it encounters a whitespace in an attribute

As title describes, the FXmlFile(const FString&) constructor fails to parse an XML that is as such: <?xml version = "1.0" ?> <parent name="aTag" link= "linkName"> <origin xyz="0.0000000000E+00 0. ...

A 5.5 level that contains a Text3DComponent in a BP crashes the engine when opened in 5.6 (and up)

zComponent - Archive - Sep 11, 2025

A 5.5 level that contains a Text3DComponent in a BP crashes the engine when opened in 5.6 (and up). The licensee has provided his analysis: Description: Level instance created in UE5.5 and re-saved ...

Post Process Animation Blueprint Crash When Using Blend Node

UE - Runtime - Anim BP - Sep 24, 2025

When using a Blend node inside a Post Process Animation Blueprint, the editor crashes while rendering thumbnails. The crash occurs because USkeletonThumbnailRenderer attempts to draw a thumbnail wit ...