CEP panel intermittently renders as blank/grey — content composited but never presented (Illustrator 2026 / CEP 12.1 / Apple Silicon)
Environment
- Adobe Illustrator 2026 (30.6.0), CEP runtime 12.1 / Chromium 99, AdobeCEP/12.1.0
- macOS on Apple Silicon; display at fractional HiDPI (CEP logs Zoom Html 1.250000)
- Custom CEP panel extension (Angular content)
Symptom
- Intermittently, on panel open, the panel shows as an empty grey pane and never populates for the remainder of the Illustrator session.
The extension page fully loads and renders: DOM is present, correctly sized, document.visibilityState === 'visible', OnLoadEnd fires. The host bridge works — adobe_cep.evalScript('1+1') returns 2.
The rendered pixels never reach the screen: setting document.body.style.background = 'red' produces no visible change in the panel, and DevTools "Capture screenshot" returns a blank image.
With CEF logging enabled (--enable-logging --v=1 --enable-gpu-service-logging): the GL context initializes successfully and raster commands run continuously, with zero GL/GPU errors. No renderer/GPU process crash is recorded.
The failure is per-panel-instance: in the same Illustrator session, other CEP panels (a sibling extension and Adobe's own OnBoarding panel) render normally.
Not recoverable by: native content resize, forced reflow/recomposite from JS, or closing and reopening the panel. Only a full Illustrator restart clears it (the panel's CEPHtmlEngine/GPU process persists across panel close and stays wedged).
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The extension renders correctly but its composited output is never presented to the panel's surface — a compositor/present-path failure inside the CEP CEF runtime, not in the extension.
Peter Coppens
shared this idea
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Matthew Danbury commented
Similar thing happening here:
Environment:
- Adobe Illustrator 2026 30.5.1
- macOS Sequoia 15.7.3
- CEPHtmlEngine12 / AdobeCEP 12.1.0 / Chrome 99.0.4844.84
- LaTeX2AI v1.0.3 and v1.1.0-rc.1
- macOS install path: /Library/Application Support/Adobe/CEP/extensions/com.isteinbrecher.latex2aiSymptoms:
- LaTeX2AI native plugin loads and opens its CEP UI containers.
- All LaTeX2AI windows show blank white/gray content.
- CEP logs update and show ClientInitialized begin/end.
- DevTools server starts on port 8088, but page shows only “Inspectable WebContents” with no inspectable target.
- Removing com.apple.quarantine from the full CEP extension did not fix it.
- Clearing ~/Library/Caches/CSXS/cep_cache did not fix it.
- Adding CEF flags --disable-gpu, --disable-gpu-compositing, and --disable-accelerated-2d-canvas was picked up by CEP but did not fix it.
- Changing UI type from ModalDialog to Panel changed the container but content remained blank.
- Replacing MainPath with a minimal no-script smoke.html still rendered blank.Conclusion:
This does not appear to be caused by LaTeX2AI HTML/JS/CSS. Illustrator launches CEPHtmlEngine for the extension but does not present web content.