I am using a Vega USB 2.0 webcam on Raspberry Pi 3 running OctoPi 0.15. The webcam works, but "Webcam stream not loaded" message always shows up in Control window. In Webcam & Timelapse settings, the webcam streaming test doesn't work. But under Timelapse Recordings, I can get a clear snapshot from the webcam when I press 'Test', also the 'Path to FFMPEG' test is successful.
I've uncommented the line camera="auto" and tried different camera_usb_options parameters in /boot/octopi.txt. The Vega USB 2.0 webcam is reported to be working with Octopi (https://github.com/foosel/OctoPrint/wiki/Webcams-known-to-work, https://elinux.org/RPi_USB_Webcams).
What else should I try to get the streamer working? Do I need to modify any webcam or streamer parameters in 'webcamd' or 'config.yaml'?