Was excited that Arlo support was added in 0.46 but having trouble with the video streams from the cameras. I assume this is because I haven’t yet configured ffmpeg. From the support docs, it gives directions for installing on debian, which I had hoped would work on hassbian on my Pi Zero W. Alas, it did not. Here is what I got from my attempts:
Yes you need to setup and configure ffmpeg for the video streams to work.
I don’t know why the command fails for you but you can try to add the line using nano instead.
$ cd /etc/apt/
$ sudo nano sources.list
add “deb http://ftp.debian.org/debian jessie-backports main” (without quotes) on a new row at the end of the document. Save and exit and you should be good to continue the installation.