Windows Error 10053 after changing database engine

[sushant]

This particular error showed up after I changed database engine from SQLite3 to PostgreSQL-

[02/Aug/2016 21:19:20] "GET /api/delet/ HTTP/1.1" 404 6205
[02/Aug/2016 21:19:25] "GET /api/delete/ HTTP/1.1" 200 7
Traceback (most recent call last):
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 138, in run
    self.finish_response()
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 180, in finish_response
    self.write(data)
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 274, in write
    self.send_headers()
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 332, in send_headers
    self.send_preamble()
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 255, in send_preamble
    ('Date: %s\r\n' % format_date_time(time.time())).encode('iso-8859-1')
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 453, in _write
    self.stdout.write(data)
  File "c:\program files (x86)\python35-32\Lib\socket.py", line 593, in write
    return self._sock.send(b)
ConnectionAbortedError: [WinError 10053] An established connection was aborted by the software in your host machine
[02/Aug/2016 21:19:25] "GET /api/delete/ HTTP/1.1" 500 59
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 2446)
[02/Aug/2016 21:19:25] "GET /api/delete/ HTTP/1.1" 200 7
Traceback (most recent call last):
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 138, in run
    self.finish_response()
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 180, in finish_response
    self.write(data)
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 274, in write
    self.send_headers()
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 332, in send_headers
    self.send_preamble()
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 255, in send_preamble
    ('Date: %s\r\n' % format_date_time(time.time())).encode('iso-8859-1')
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 453, in _write
    self.stdout.write(data)
  File "c:\program files (x86)\python35-32\Lib\socket.py", line 593, in write
    return self._sock.send(b)
ConnectionAbortedError: [WinError 10053] An established connection was aborted by the software in your host machine

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 141, in run
    self.handle_error()
  File "C:\Users\sushant\Desktop\projects\drfapi\venv\lib\site-packages\django\core\servers\basehttp.py", line 92, in handle_error
    super(ServerHandler, self).handle_error()
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 368, in handle_error
    self.finish_response()
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 180, in finish_response
    self.write(data)
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 274, in write
    self.send_headers()
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 331, in send_headers
    if not self.origin_server or self.client_is_modern():
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 344, in client_is_modern
    return self.environ['SERVER_PROTOCOL'].upper() != 'HTTP/0.9'
TypeError: 'NoneType' object is not subscriptable

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\program files (x86)\python35-32\Lib\socketserver.py", line 628, in process_request_thread
    self.finish_request(request, client_address)
  File "c:\program files (x86)\python35-32\Lib\socketserver.py", line 357, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "C:\Users\sushant\Desktop\projects\drfapi\venv\lib\site-packages\django\core\servers\basehttp.py", line 99, in __init__
    super(WSGIRequestHandler, self).__init__(*args, **kwargs)
  File "c:\program files (x86)\python35-32\Lib\socketserver.py", line 684, in __init__
    self.handle()
  File "C:\Users\sushant\Desktop\projects\drfapi\venv\lib\site-packages\django\core\servers\basehttp.py", line 179, in handle
    handler.run(self.server.get_app())
  File "c:\program files (x86)\python35-32\Lib\wsgiref\handlers.py", line 144, in run
    self.close()
  File "c:\program files (x86)\python35-32\Lib\wsgiref\simple_server.py", line 35, in close
    self.status.split(' ',1)[0], self.bytes_sent
AttributeError: 'NoneType' object has no attribute 'split'
----------------------------------------
Performing system checks...

If there is save() method in the code, it is performed twice, once without errors, but does not stop there, this error message shows up and is saved again.

[Tim Graham]

I guess this may be ​a problem in Python instead of an issue with Django. If you can explain why Django is at fault, feel free to reopen. If you need help debugging, please see TicketClosingReasons/UseSupportChannels.

See also #26072.