Unreal Engine Issues

Nanite: unused VertexInterpolator node disables Opacity Mask (material renders opaque)

On Nanite meshes, placing a VertexInterpolator node in a material graph without using it (unconnected, or routed through a disabled static switch) silently breaks the Opacity Mask and the material r ...

Mutable Dataless Generation - Regenerate Imported Models Crash

Crash when working with Dataless Mutable content. When selecting meshes in the instance, there is a crash in RegenerateImportedModels. ...

Crash editing Primary Assets Label in ShooterGame assets in 5.8

Niagara NDC GPU Instance Counter leak

In NiagaraDataChannelData.cpp, FNiagaraDataChannelDataProxy::EndFrame enqueues a GPU readback for each entry in PendingGPUReadbackBuffers, but the corresponding FNiagaraGPUInstanceCountManager::Free ...

Water plugin's RVT/ISR shader permutations fail PSO creation with instanced stereo (D3D12 SM6)

With Instanced Stereo Rendering enabled and the Water plugin enabled (default), PSO precaching speculatively compiles WorldGridMaterial × FWaterVertexFactory* permutations for the Runtime Virtual Te ...

UBackgroundBlur crashes at PSO creation under D3D12 SM6 when stereo rendering is enabled

Any Slate widget that triggers the Slate post-process blur (e.g., a UBackgroundBlur with non-zero strength) hits a fatal D3D12 CreateGraphicsPipelineState failure on first render. The fatal is funne ...

Instanced Actors: PCG on RuntimeGrid "None" assigns created IAManagers RuntimeGrid "MainGrid", causing cross-grid reference

Context PCG can be used to spawn Instanced Actors via the PCG IA Interop plugin, that makes Spawned Instanced Actors available as node. When a PCGActor placed in the level runs a PCG graph that spa ...

[CrashReport][Crash] Engine!FSceneViewport::UpdateViewportRHI() [SceneViewport.cpp]

#200 crash out of 2101 in UE 5.8 on Windows#34 crash for UE - Rendering - Architecture in UE 5.8 on Windows#20 crash for UE - Rendering - Architecture - RHI in UE 5.8 on WindowsAssertion failed: IsI ...

Assert crash when playing Groom Cache with Card Mesh LOD

Playing a Guides Groom Cache while Card Mesh LOD (Guide-Based) is active causes an assert in RunHairStrandsInterpolation_Cards when the renderer switches to Card LOD. Assert location:Plugins/Runtim ...

Niagara Mesh Renderer registers NumParticles x NumMeshVariants TLAS instances

When using the Niagara Mesh Renderer with multiple mesh variants selected via MeshIndex, the number of TLAS instances allocated is NumParticles × NumMeshVariants and enabling the Path Tracer can ca ...