Summary
On a hybrid-GPU Windows laptop (NVIDIA discrete + Intel integrated), after the first 3D viewport renders, every top-level Slate popup and menu (File, Edit, Window, Help, context menus, dropdowns) renders an offset copy of the main window’s backbuffer instead of its actual contents. The corruption persists for the entire editor session.
RHI: D3D12 (default) — reproduces. Vulkan — reproduces.
RHI: D3D11 (-dx11) — clean, no corruption.
This is present in 5.8.2 as well; 5.8.3 does NOT fix it.
Please select what you are reporting on:
Creative
What Type of Bug are you experiencing?
UI/Tools
Steps to Reproduce
Launch the UE 5.8.3 editor with default RHI (D3D12 / SM6) on the machine above. (Differs from -dx11.)
Open any project and any level.
Let the first 3D viewport render (a frame or two is enough).
Open any top-level Slate popup: menu bar File / Edit / Window / Help, a context (right-click) menu, a dropdown, or a combo box.
Observed: the popup shows an offset/repeated copy of the main window’s backbuffer instead of the actual menu; menus are unreadable/unusable.
The corruption persists for the entire session (does not self-heal).
Quit and relaunch with -dx11 → popups render correctly.
Expected Result
Launching the editor with the default D3D12 RHI should render every top-level Slate menu and popup (the File / Edit / Window / Help menu bar, right-click context menus, dropdowns, combo boxes) correctly — showing their actual menu items and text. Menus should be crisp, readable, and fully interactive, independent of whatever is being rendered in the 3D viewport behind them.
Observed Result
After the first 3D viewport frame renders, every top-level Slate popup/menu renders an offset copy of the main window’s backbuffer instead of its own contents. The popup appears as a garbled, shifted duplicate of the main viewport image; the actual menu items are invisible and unreadable, so File / Edit / Window / Help are unusable. The corruption begins only after the first 3D viewport draw and persists for the entire editor session. Launching the exact same project with -dx11 (D3D11 / SM5) renders all menus correctly — so the symptom is specific to the D3D12/Vulkan path on this hybrid-GPU laptop.
Platform(s)
Windows — Windows 11 25H2 x64, build 10.0.26200.9457. Reproduced with D3D12 (SM6) and Vulkan; D3D11 is clean
