"Notification registration failed" / "sslv3 alert certificate unknown"

Configuration
1

I’ve got SSL set up with a self-signed cert, exposed to outside… push notifications work on my laptop in Firefox, but not on my phone, neither in Firefox nor Chrome. I immediately get a “Notification registration failed” message (generally the toggle doesn’t even move) and somewhere in the vicinity of when I get that, I’ll get this in Hass’s log:

Error in HTTPServer.tick
Traceback (most recent call last):
  File "/home/hass/.homeassistant/deps/cherrypy/wsgiserver/__init__.py", line 2019, in start
self.tick()
  File "/home/hass/.homeassistant/deps/cherrypy/wsgiserver/__init__.py", line 2086, in tick
s, ssl_env = self.ssl_adapter.wrap(s)
  File "/home/hass/.homeassistant/deps/cherrypy/wsgiserver/ssl_builtin.py", line 67, in wrap
server_side=True)
  File "/usr/lib/python3.5/ssl.py", line 377, in wrap_socket
_context=self)
  File "/usr/lib/python3.5/ssl.py", line 752, in __init__
self.do_handshake()
  File "/usr/lib/python3.5/ssl.py", line 988, in do_handshake
self._sslobj.do_handshake()
  File "/usr/lib/python3.5/ssl.py", line 633, in do_handshake
self._sslobj.do_handshake()
ssl.SSLError: [SSL: SSLV3_ALERT_CERTIFICATE_UNKNOWN] sslv3 alert certificate unknown (_ssl.c:645)

What certificate, exactly? And why is the laptop fine? They’re connected to the same WiFi network…

E: I just noticed that this seems to break the frontend completely, it just loads and loads until I restart Hass…

2

Do you already know what the problem was and the solution? I now get exactly the same report myself.

3

Also getting SSLV3_ALERT_CERTIFICATE_UNKNOWN all of a sudden now in my log

4

Same here. Don’t have a clue.