"Something went wrong" aiohttp.http_exceptions.BadStatusLine: invalid HTTP method

Home assistant “stopped working”. When going to the frontend with the browser we get “Something went wrong:” and no log in input fields anymore

Attempting to fix it I upgraded python to 3.7.0 and homeassistant to 0.77.3
I removed the config back down to this:

---
homeassistant:
  # Name of the location where Home Assistant is running
  name: Home
  unit_system: metric
  # Pick yours from here: http://en.wikipedia.org/wiki/List_of_tz_database_time_zones
  time_zone: Pacific/Auckland
# Enables the frontend
frontend:

Home assistant starts but every time any browser hits the web interface it’s just this:

2018-09-15 18:48:27 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/home/brenda/.pyenv/versions/3.7.0/lib/python3.7/site-packages/aiohttp/web_protocol.py", line 242, in data_received
    messages, upgraded, tail = self._request_parser.feed_data(data)
  File "aiohttp/_http_parser.pyx", line 519, in aiohttp._http_parser.HttpParser.feed_data
aiohttp.http_exceptions.BadStatusLine: invalid HTTP method
2018-09-15 18:48:27 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/home/brenda/.pyenv/versions/3.7.0/lib/python3.7/site-packages/aiohttp/web_protocol.py", line 242, in data_received
    messages, upgraded, tail = self._request_parser.feed_data(data)
  File "aiohttp/_http_parser.pyx", line 519, in aiohttp._http_parser.HttpParser.feed_data
aiohttp.http_exceptions.BadStatusLine: invalid HTTP method
2018-09-15 18:48:27 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/home/brenda/.pyenv/versions/3.7.0/lib/python3.7/site-packages/aiohttp/web_protocol.py", line 242, in data_received
    messages, upgraded, tail = self._request_parser.feed_data(data)
  File "aiohttp/_http_parser.pyx", line 519, in aiohttp._http_parser.HttpParser.feed_data
aiohttp.http_exceptions.BadStatusLine: invalid HTTP method
2018-09-15 18:48:27 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/home/brenda/.pyenv/versions/3.7.0/lib/python3.7/site-packages/aiohttp/web_protocol.py", line 242, in data_received
    messages, upgraded, tail = self._request_parser.feed_data(data)
  File "aiohttp/_http_parser.pyx", line 519, in aiohttp._http_parser.HttpParser.feed_data
aiohttp.http_exceptions.BadStatusLine: invalid HTTP method

and nobody can log in.

Any help appreciated on why i can’t use hass anymore

i set a new http: base_url to the ip (instead of the dns entry) and it started working.
I put it back to the dns entry and it stayed working.

No idea what caused this but it seems to be okay again

worked it out - letsencrypt cert had expired, which made a whole bunch of things log not-so-useful errors.