FGameplayTagCountContainer::Reset() leaves explicit tag state and causes counts to accumulate

UE - Gameplay - Gameplay Tags - Aug 4, 2026

[Summary] In UE 5.7 and later, if a tag is added once to an FGameplayTagCountContainer, the container is reset, and the same tag is added once more, GetExplicitTagCount() returns 2 instead of the e ...

Values passed through VertexInterpolators are incorrect in the pixel shader on Niagara mesh particles when material uses SubUV animation

UE - Rendering - Architecture - Niagara - Jul 29, 2026

Passing through the vertex interpolator, the DebugFloat3Values output appears garbled, but if you remove the VertexInterpolator the particle’s position is accurately returned. This happens with Part ...

BlendSpace Loop Boundary Produces Inconsistent Sync Marker Data andTriggers an AnimSequence Follower Assertion

UE - Runtime - Animation - Jul 22, 2026

Summary In UE 5.7.4, when a looping BlendSpace with Match Sync Phases enabled plays as a SyncGroup Leader and crosses its loop boundary during a transition to an external AnimSequenceFollower in th ...

Editor crashes in FAsyncLoadingThread2::ProcessLoadedPackagesFromGame when Level Blueprint references external actor

UE - World Creation - Worldbuilding Tools - Level Instances - Jun 26, 2026

Adding a reference to an external actor in the level blueprint causes the package for the actor to be put in the import table of the level. In some cases, the actor package can end up calling postlo ...

Material Layers cannot be re-ordered by dragging in the Material Layer Parameters tab

UE - Rendering - Architecture - Materials - Jun 9, 2026

Material Layers cannot be re-ordered by dragging in the Material Layer Parameters tab even though there is UI for dragging the rows and the rows appear to be draggable. ...

Editor crashes when Material Layer visibility is toggled after removing a Material Layer in Parent

UE - Rendering - Architecture - Materials - Jun 9, 2026

When a Material Layer is removed from a Parent Material, the Parent Material updates correctly in the viewport, but any Child Material Instance do not update correctly in the viewport until the Chil ...

Adding/Removing a Material Layer on a Parent Material doesn't propagate to Children correctly

UE - Rendering - Architecture - Materials - Jun 9, 2026

When a Material Layer is added to or removed from a Parent Material the layer changes don’t automatically propagate to Child Materials correctly even if the Parent Material is saved. The Child mate ...

Toggling Material Layer visibility in Parent Material doesn't propagate to children

UE - Rendering - Architecture - Materials - Jun 9, 2026

When Material layer visibility is toggled on the Parent Material in a Material hierarchy, only the Parent’s layer visibility is affected, the children are not. Saving the Parent material has no effe ...

Sequencer - if you set the Take Separator to - rather than _ the New Take naming will mess up

UE - CAPT - Sequencer - Jun 9, 2026

When using a non-default take separator (eg "-") the "New Take" option produces a malformed proposed name for the take. ...