2018-02-05 19:59:38,357 - synapse.http.server - 183 - ERROR - GET-132067- Failed handle request synapse.http.server._async_render on <synapse.rest.ClientRest
Resource object at 0x7f9dae55b590>: <XForwardedForRequest at 0x7f9d7856c2d8 method=GET uri=/_matrix/client/r0/rooms/!vfFxDRtZSSdspfTSEr:matrix.org/joined_mem
bers?access_token=<redacted> clientproto=HTTP/1.1 site=8008>: Traceback (most recent call last):
  File "/home/travis/.synapse/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1532, in unwindGenerator
    return _inlineCallbacks(None, gen, Deferred())
  File "/home/travis/.synapse/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1386, in _inlineCallbacks
    result = g.send(result)
  File "/home/travis/.synapse/local/lib/python2.7/site-packages/synapse/rest/client/v1/room.py", line 408, in on_GET
    requester, room_id,
  File "/home/travis/.synapse/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1532, in unwindGenerator
    return _inlineCallbacks(None, gen, Deferred())
--- <exception caught here> ---
  File "/home/travis/.synapse/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1386, in _inlineCallbacks
    result = g.send(result)
  File "/home/travis/.synapse/local/lib/python2.7/site-packages/synapse/handlers/message.py", line 449, in get_joined_members
    "Getting joined members after leaving is not implemented"
exceptions.NotImplementedError: Getting joined members after leaving is not implemented