Unreal Engine Issues

Cinematic Prestreaming does not work in Shipping Builds

When the Cinematic Prestreaming plugin is used to generate and cache Virtual Texture Feedback requests, they work when played back in Unreal Editor. A Licensee has reported that they do not improve ...

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

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 ...

Saving Behavior Tree with Blueprint task inheriting from native class invalidates Blackboard key when BP contains a function

A regression introduced in UE 5.6 causes Blackboard key selectors in Blueprint tasks to become invalid when the Blueprint inherits from a native subclass of UBTTask_MoveTo (or UBTTask_BlackboardBase ...

No way to scroll through ShowDebug EnhancedInput output

Modifiers do not behave as expected when adding conflicting mappings of different priorities

Objects without custom delta properties can return false for CanSkipUpdate with net.PushModelSkipUndirtiedReplication enabled

This seems to occur after receiving a Nak for certain actors. FObjectReplicator::ReceivedNak will decrement SendingRepState.CustomDeltaChangeIndex even if the object has no custom delta properties. ...

Regression with RecomputeTangents on SkeletalMeshes in 5.6

Licensee noticed a regression in 5.6 where the non-masked recompute tangents option doesn't work anymore. The option is called "Enabled with no mask" in 5.6 but "All" in 5.5. Under the hood, this se ...

Rect Light not rendered correctly when using Virtual Texture as source texture

Licensees have reported that this issue occurs when rendering from the command line: Rectangular lights with virtual textures do not render when you run the "Render (Remote)" button in the Editor, a ...

Console command “showflag.rendering 0” causes crash

A crash occurs when the console command “showflag.rendering 0” is executed. This does not occur in UE5.5, so it is a iassue in UE5.6. ...

Virtual Shadow Maps on Spot Lights cause a blocky presentation similar to an incorrect mip level

Spot Lights may present with very blocky shadow artefacts when a long attentuation radius is provided with a small cone angle. In extreme cases, this causes the VSMs to invalidate every frame. Notab ...