Django application 504 error after saving model
It is probably due to this bug https://github.com/pyca/cryptography/issues/2299
How to fix discussed herehttps://github.com/pyca/cryptography/issues/2473
Which seems to say uninstall python Cryptography library and then pip install version 1.1 of it
This error showed up for me by django-ses calling for the rate limit through boto's make_request in the connections module. Reverting cryptography 1.5 to 1.1 fixed my errors.