pywbem.exceptions.ConnectionError: SSL error

os version: centos7
esxi version: esxi 6.5
python version: python 2.7.5
pywbem version: 0.12.3

Traceback (most recent call last):
File “/usr/lib64/nagios/plugins/check_esxi_hardware.py”, line 703, in
instance_list = wbemclient.EnumerateInstances(classe)
File “/usr/lib/python2.7/site-packages/pywbem/cim_operations.py”, line 2229, in EnumerateInstances
**extra)
File “/usr/lib/python2.7/site-packages/pywbem/cim_operations.py”, line 1616, in _imethodcall
conn_id=self.conn_id)
File “/usr/lib/python2.7/site-packages/pywbem/cim_http.py”, line 790, in wbem_request
client.endheaders()
File “/usr/lib64/python2.7/httplib.py”, line 1037, in endheaders
self._send_output(message_body)
File “/usr/lib64/python2.7/httplib.py”, line 881, in _send_output
self.send(msg)
File “/usr/lib/python2.7/site-pac kages/pywbem/cim_http.py”, line 468, in send
self.connect() # pylint: disable=no-member
File “/usr/lib/python2.7/site-packages/pywbem/cim_http.py”, line 594, in connect
“SSL error %s: %s” % (arg.__class__, arg))
pywbem.exceptions.ConnectionError: SSL error : unexpected eof

The script appears to be able to connect as the OK alarm identifies the system information and serial number etc.

Do you have any idea what this error means?

Thanks