Heterogeneous Volume Actor causes ensures to trigger in Debug builds

UE - Niagara - Aug 24, 2025

When a heterogeneous volume actor is used with a volume material in a debug build, the following ensures are triggered: Ensure condition failed: UniformBufferValue || EnumHasAnyFlags(AutomaticallyBo ...

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected

UE - Rendering Architecture - Materials - Aug 24, 2025

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected. The licensee noticed this in a ...

Slow editor/PIE loading of UWorldPartitionHLODSourceActorsFromCell

UE - World Creation - Worldbuilding Tools - World Partition - Aug 22, 2025

Loading UWorldPartitionHLODSourceActorsFromCell takes a lot of time in editor + PIE when it contains a lot of actors per UWorldPartitionHLODSourceActorsFromCell (between 2K and 2K actors). ...

Slate text layout AllowPerCharacterWrapping issue

Customer-reported bug in TextLayout (AllowPerCharacterWrapping): Issue seems tied to bHasTrailingText handling in TextLayout.cpp (~line 694). The remainder handling after wrap inserts an extra break ...

Missing PSO Precaches in the engine

UE - Rendering Architecture - RHI - Aug 20, 2025

A licensee wanted to report some missing PSO Precaching they found, which they have fixed locally: 1. UCableComponent doesn't implement CollectPSOPrecacheData or call CheckPSOPrecachingAndBoostPri ...

Physics Mover: AI movement and collisions can cause sharp increase in velocity

UE - Gameplay - Player Movement - Mover - Aug 19, 2025

A pawn using the physics mover and using AI movement can sometimes gain an ton of velocity quickly upon colliding with another physics object. It seems to fix it self and revert back to it's origina ...

Sub-world partitions do not properly handle partial editor loading as world partition standalone level instances' spatially loaded actors do not get loaded even when the Level Instance is force loaded or loaded in by region.

UE - World Creation - Worldbuilding Tools - World Partition - Aug 19, 2025

Context Level Instancing is a level-based workflow designed to improve and streamline the level editing experience. In a standalone Level Behavior, when the Level Instance Actor is loaded through it ...

HighResShot Alpha always 255

Expected behavior is that screenshot alpha should be 0 for pixels that did not have anything rendered into them. ...

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 ...