Summary
Unreal Editor 5.8 consistently hard-freezes within seconds to roughly two minutes after loading a project when using DirectX 12. The hang is unrecoverable: Task Manager cannot end UnrealEditor, and a full system restart is required. The same hardware and projects work in UE 5.6. The issue reproduces in both a custom project and Epic’s stock Intro sample project. Launching with -d3d11 avoids the DX12 hard freeze, indicating a UE 5.8 DX12 regression.
What Type of Bug are you experiencing?
Rendering (Graphics / Niagara)
Steps to Reproduce
- On Windows 11, launch UnrealEditor.exe from Unreal Engine 5.8 normally (DX12; no launch flags).
- Open any project. The issue reproduces with both a custom project and Epic’s stock Intro sample project.
- Leave the editor open or interact with the editor UI/viewport.
- Within seconds to approximately two minutes, observe the editor and GPU become unresponsive.
- Attempt to end UnrealEditor from Task Manager; Task Manager also becomes unresponsive and a full restart is required.
Expected Result
Unreal Editor should remain responsive when running under DX12, and Slate/viewport rendering should complete normally, as it does on the identical system and project in UE 5.6.
Observed Result
The editor hard-freezes and cannot be terminated. The log reports a D3D12 GPU timeout, with active GPU breadcrumbs ending in Slate viewport rendering:
LogD3D12RHI: Warning: GPU timeout: A payload (…) on the […, 3D] queue has not completed after 5.000001 seconds.
LogRHI: Warning: Active GPU breadcrumbs:
(ID: …) [Active] RenderGraphExecute - Slate
(ID: …) [Active] SlateUI Title = MyProject - Unreal Editor
(ID: …) [Active] EndDrawingViewport
The same result occurs with ray tracing disabled using -noraytracing.
Affects Versions
5.8
Platform(s)
Windows
For crash reports, include your callstack
No Crash Reporter callstack is produced because this is a hard GPU/editor hang rather than a normal process crash.
Additional Notes
Environment:
- CPU: AMD Ryzen 5 9600X
- GPU: AMD Radeon RX 9070 XT 16GB (secondary AMD Radeon™ Graphics iGPU)
- RAM: 32GB DDR5
- Motherboard: Gigabyte B850 Gaming X WiFi 6E
- OS: Windows 11 Pro 25H2
- AMD driver: Adrenalin 26.6.4
Troubleshooting completed:
- Full DDU clean wipe in Safe Mode followed by factory-reset Adrenalin reinstall; issue persists.
- Tested with -noraytracing; issue persists.
- sfc /scannow found no integrity violations.
- Reproduced on Epic’s stock Intro sample, ruling out project-specific content.
- Pinned UnrealEditor.exe to the RX 9070 XT in Windows Graphics settings; issue persists.
Workaround: launching with -d3d11 avoids the DX12 hard freeze. A separate, less severe hang was observed once when closing a PIE window under DX11; its breadcrumb trace is available if useful.
Related report describing matching UE 5.8 UI-interaction freezes not present in 5.7.4 on different hardware: 5.8 Freezing on UI interaction