Without doing any changes, when I tried to login to the web gui I got the following screen 
A reboot fixed the issue, but still really confusing:
Stack trace
Traceback (most recent call last):
File "/usr/lib/python3.6/site-packages/foris/middleware/backend_data.py", line 54, in __call__
data = current_state.backend.perform("web", "get_data")
File "/usr/lib/python3.6/site-packages/foris/backend.py", line 74, in perform
raise e
File "/usr/lib/python3.6/site-packages/foris/backend.py", line 61, in perform
response = self._instance.send(module, action, data)
File "/usr/lib/python3.6/site-packages/foris_client/buses/ubus.py", line 104, in send
"final": True, "multipart": False, "request_id": request_id
RuntimeError: Object 'foris-controller-web' was not found.
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/lib/python3.6/site-packages/foris/middleware/reporting.py", line 93, in __call__
return self.app(environ, start_response)
File "/usr/lib/python3.6/site-packages/foris/middleware/backend_data.py", line 60, in __call__
return self.app(environ, start_response)
File "/usr/lib/python3.6/site-packages/bottle_i18n.py", line 68, in __call__
return self.app(e,h)
File "/usr/lib/python3.6/site-packages/bottle.py", line 979, in __call__
return self.wsgi(environ, start_response)
File "/usr/lib/python3.6/site-packages/bottle.py", line 954, in wsgi
out = self._cast(self._handle(environ))
File "/usr/lib/python3.6/site-packages/bottle.py", line 862, in _handle
return route.call(**args)
File "/usr/lib/python3.6/site-packages/bottle.py", line 1740, in wrapper
rv = callback(*a, **ka)
File "/usr/lib/python3.6/site-packages/bottle.py", line 3639, in wrapper
result = func(*args, **kwargs)
File "/usr/lib/python3.6/site-packages/foris/config/__init__.py", line 870, in top_index
if not current_state.password_set: # auto login if no password is set
AttributeError: 'ForisState' object has no attribute 'password_set'
Environment
{'CONTENT_LENGTH': '0',
'DOCUMENT_ROOT': '/www',
'GATEWAY_INTERFACE': 'CGI/1.1',
'HTTPS': 'on',
'HTTP_ACCEPT': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8',
'HTTP_ACCEPT_ENCODING': 'gzip, deflate, br',
'HTTP_ACCEPT_LANGUAGE': 'en-GB,en-US;q=0.9,en;q=0.8,sv;q=0.7,fr;q=0.6',
'HTTP_CONNECTION': 'keep-alive',
'HTTP_COOKIE': 'foris.session=SESSION_COOKIE; '
'foris.ws.session=SESSION',
'HTTP_HOST': '172.16.200.1',
'HTTP_REFERER': 'https://LOCAL_IP/',
'HTTP_UPGRADE_INSECURE_REQUESTS': '1',
'HTTP_USER_AGENT': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) '
'AppleWebKit/537.36 (KHTML, like Gecko) '
'Chrome/71.0.3578.98 Safari/537.36',
'PATH_INFO': '/',
'PATH_TRANSLATED': '/www/',
'QUERY_STRING': '',
'REDIRECT_STATUS': '200',
'REMOTE_ADDR': 'SOURCE_IP',
'REMOTE_PORT': '62997',
'REQUEST_METHOD': 'GET',
'REQUEST_SCHEME': 'https',
'REQUEST_URI': '/foris/config/',
'SCRIPT_FILENAME': '/www/foris/config',
'SCRIPT_NAME': '/foris/config',
'SERVER_ADDR': 'LOCAL_IP',
'SERVER_NAME': 'LOCAL_IP',
'SERVER_PORT': '443',
'SERVER_PROTOCOL': 'HTTP/1.1',
'SERVER_SOFTWARE': 'lighttpd/1.4.50',
'SSL_CIPHER': 'ECDHE-RSA-AES128-GCM-SHA256',
'SSL_CIPHER_ALGKEYSIZE': '128',
'SSL_CIPHER_USEKEYSIZE': '128',
'SSL_PROTOCOL': 'TLSv1.2',
'bottle.app': <bottle.Bottle object at 0xc95450>,
'bottle.get': <bottle.FormsDict object at 0x111b320>,
'bottle.raw_path': '/',
'bottle.request': <LocalRequest: GET https://172.16.200.1/foris/config/>,
'bottle.request.query': <bottle.FormsDict object at 0x111b320>,
'bottle.request.urlparts': SplitResult(scheme='https', netloc='172.16.200.1', path='/foris/config/', query='', fragment=''),
'bottle.route': <GET '/' {'template_adapter': <class 'bottle.Jinja2Template'>}>,
'foris.backend': UbusSender('/var/run/ubus.sock'),
'foris.language': 'en',
'foris.session': <foris.middleware.sessions.SessionForisProxy object at 0x10b6930>,
'foris.session.data': {'_messages': [],
'csrf_token': 'TOKEN'},
'foris.session.id': '00000000000000000000000000000000',
'foris.version': '98.17',
'route.handle': <GET '/' {'template_adapter': <class 'bottle.Jinja2Template'>}>,
'route.url_args': {},
'wsgi.errors': <flup.server.fcgi_base.OutputStream object at 0x10bde90>,
'wsgi.input': <flup.server.fcgi_base.InputStream object at 0x10963e0>,
'wsgi.multiprocess': False,
'wsgi.multithread': True,
'wsgi.run_once': False,
'wsgi.url_scheme': 'https',
'wsgi.version': (1, 0)}