While troubleshooting the brief white flash when closing plugin windows, I discovered a reproducible behavior linked to the Metal Based GFX Rendering setting.
Steps to Reproduce
- Launch Renoise.
- In Preferences → GUI, set Use Metal Based GFX Rendering = ON .
- Toggle ON/OFF — no flash is observed.
- Turn Metal Based GFX Rendering OFF .
- Instantiate any VST3 plugin (tested with UVI Falcon, Cherry Audio DCO-106, and even Apple stock plugins).
- Close the plugin window → brief white flash occurs.
- Turn Metal Based GFX Rendering ON again.
- The entire Renoise UI flashes white momentarily.
Notes
- This happens consistently on my setup.
- On a fresh Renoise launch, toggling Metal rendering alone does not cause a flash — it only starts after closing a VST3 with Metal rendering OFF.
- Behavior occurs regardless of sandboxing settings.
- Wrapping the same plugin in Blue Cat PatchWork prevents the flash.
System
- Mac mini M2 Pro
- macOS 15.5 Sequoia
- Renoise 3.5.2
- External monitor only (no built-in display)
Accessibility Impact
This visual flash can be disruptive for neurodivergent users or those with sensory sensitivity, so it would be great to address alongside other Metal rendering work.
Related Thread: macOS 15.5: UI Flash & Resize Artifact in Redux 1.4 Under Logic Pro 11.2.1