How to fix black screen on Filteronme camera?

The #1 cause is app order: open Filteronme before you open the app you're using it in (Zoom, Discord, OBS, etc.). Windows needs Filteronme open for the camera to work at all; on Mac 2.1+ you can close Filteronme again once you've selected the camera.

Confirm Filteronme has control of your camera — you should see yourself in its preview — before switching to the other app.

Still black? Reboot the Filteronme app first — quit it fully and reopen it. If the screen stays black, work through the full fix ladder in how to fix most problems: it covers camera permissions, reinstalling the camera extension, and a full reinstall as the last resort.