AssertionError: Hop-by-hop headers not allowed

Traceback (most recent call last):

  File "/Library/Python/2.7/site-packages/django/core/servers/basehttp.py", line 283, in run
    self.result = application(self.environ, self.start_response)

  File "/Library/Python/2.7/site-packages/django/contrib/staticfiles/handlers.py", line 68, in __call__
    return self.application(environ, start_response)

  File "/Library/Python/2.7/site-packages/django/core/handlers/wsgi.py", line 284, in __call__
    start_response(status, response_headers)

  File "/Library/Python/2.7/site-packages/django/core/servers/basehttp.py", line 373, in start_response
    assert not is_hop_by_hop(name),"Hop-by-hop headers not allowed"

AssertionError: Hop-by-hop headers not allowed