Can't Set Resolution or Framerate in /boot/octopi.txt

Octolapse 0.4.1. OctoPrint 1.5.3 Python 2.7.16. OctoPi 0.17.0. Camera Logitech C920

Uncommenting the usb_camera_options line in /boot/octopi.txt causes the dreaded pink "Error Loading Webcam Settings" error box to appear.

Event attempting to set the default values generates the error as here:

Additional options to supply to MJPG Streamer for the USB camera

See for available options

Defaults to a resolution of 640x480 px and a framerate of 10 fps

camera_usb_options="-r 640x480 -f 10"

Only commenting-out the line enables Octolapse. Any suggestions?

Edit: Hmmmm... looks like the hashtag borks the markdown! Sorry 'bout that, but I'm not sure what the work-around is.