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

UE - ACT Character - Sequencer - Jun 9, 2026

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

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

UE - Rendering - Architecture - Jun 8, 2026

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

UE - Runtime - Mutable - Jun 8, 2026

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

Niagara NDC GPU Instance Counter leak

UE - Rendering - Architecture - Niagara - Jun 5, 2026

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)

UE - Rendering - RHI - Jun 4, 2026

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

UE - AI Workflows - UI Systems - Slate - Jun 4, 2026

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 ...

Crash in UWidgetAnimation::CreateDirectorInstance when switching resolution

UE - ACT Character - Sequencer - Jun 2, 2026

Hello, We've encountered a crash in UWidgetAnimation::CreateDirectorInstance when repeatedly switching resolutions. We've had it for a while but it's not until recently that we've found a consisten ...

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

UE - Graphics Tools - PCG - Graph - May 30, 2026

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]

UE - Rendering - RHI - May 29, 2026

#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 ...