synapse.http.server - 102 - ERROR - POST-36609 - Failed handle request via <function _async_render_POST at 0x7fd81b836938>: <SynapseRequest at 0x7fd8183d3320 method=POST uri=/_matrix/media/v1/upload?access_token=<redacted>&filename=15279022308169654444447737565.jpg clientproto=HTTP/1.0 site=8008>: Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 653, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1442, in gotResult
    _inlineCallbacks(r, g, deferred)
  File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1384, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "/usr/local/lib/python2.7/dist-packages/twisted/python/failure.py", line 422, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
--- <exception caught here> ---
  File "/usr/local/lib/python2.7/dist-packages/synapse/http/server.py", line 79, in wrapped_request_handler
    yield h(self, request)
  File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1384, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "/usr/local/lib/python2.7/dist-packages/twisted/python/failure.py", line 422, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
  File "/usr/local/lib/python2.7/dist-packages/synapse/rest/media/v1/upload_resource.py", line 97, in _async_render_POST
    content_length, requester.user
  File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1384, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "/usr/local/lib/python2.7/dist-packages/twisted/python/failure.py", line 422, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
  File "/usr/local/lib/python2.7/dist-packages/synapse/rest/media/v1/media_repository.py", line 164, in create_content
    None, media_id, media_id, media_type,
  File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1384, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "/usr/local/lib/python2.7/dist-packages/twisted/python/failure.py", line 422, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
  File "/usr/local/lib/python2.7/dist-packages/synapse/rest/media/v1/media_repository.py", line 616, in _generate_thumbnails
    t_width, t_height, t_type,
  File "/usr/local/lib/python2.7/dist-packages/twisted/python/threadpool.py", line 250, in inContext
    result = inContext.theWork()
  File "/usr/local/lib/python2.7/dist-packages/twisted/python/threadpool.py", line 266, in <lambda>
    inContext.theWork = lambda: context.call(ctx, func, *args, **kw)
  File "/usr/local/lib/python2.7/dist-packages/twisted/python/context.py", line 122, in callWithContext
    return self.currentContext().callWithContext(ctx, func, *args, **kw)
  File "/usr/local/lib/python2.7/dist-packages/twisted/python/context.py", line 85, in callWithContext
    return func(*args,**kw)
  File "/usr/local/lib/python2.7/dist-packages/synapse/rest/media/v1/thumbnailer.py", line 60, in scale
    return self._encode_image(scaled, output_type)
  File "/usr/local/lib/python2.7/dist-packages/synapse/rest/media/v1/thumbnailer.py", line 96, in _encode_image
    output_image.save(output_bytes_io, self.FORMATS[output_type], quality=80)
  File "/usr/local/lib/python2.7/dist-packages/PIL/Image.py", line 1935, in save
    save_handler(self, fp, filename)
  File "/usr/local/lib/python2.7/dist-packages/PIL/JpegImagePlugin.py", line 622, in _save
    raise IOError("cannot write mode %s as JPEG" % im.mode)
exceptions.IOError: cannot write mode RGBA as JPEG