I am also getting the multibackend error when attempting to send a push. HASS installed using all in one installer on an RPi3 running raspbian jessie. Tried the above suggestions to no avail (including modifying the line in html5.py). Anyone have any updates to this? Thanks!
Yep. Same issue for me, too. It looks like everything is good all the way to making the html5_push config file, but I get the multibackend error as well. Any status on a fix?
I found that if I ran the following two commands from within the venv as user hass:
pip list | grep pywebpush
pip list | grep cryptography
I got nothing (even though I was sure I ran them from the venv.
Went back and re-ran the pip install commands from within the venv, rebooted, and re-ran the pip list commands, and they are now there (thanks to @rpitera) :
(hass_venv) hass@homeassistant:/home/pi$ pip list | grep pywebpush
pywebpush (0.5.0)
(hass_venv) hass@homeassistant:/home/pi$ pip list | grep cryptography
cryptography (1.5.2)
However, I have no html5pushregistration file, and registering my Chrome browser (from macbook pro or android) both fails registration. No file is created, and nothing appears in my logs. I thought I was so close to getting this to work 