500 internal server error on log in attempt

[RichardNevell]

Trying to log in produces the following error text:

Internal server error
<ExceptionInfo [Exception: Expected x-www-form-urlencoded response from MediaWiki, but got something else: 'Please set a user-agent and respect our robot policy https://w.wiki/4wJS. See also T400119.\n'] (11 frames, last=Callpoint('initiate', 93, 'mwoauth.functions', '/home/hatnote/virtualenvs/plinth/local/lib/python2.7/site-packages/mwoauth/functions.py', 141, ' "{0}".format(repr(r.content)))'))>

Error type: http://docs.python.org/2/library/exceptions.html#exceptions.Exception