I'm trying on FC24, using python-ovirt-engine-sdk4-4.1.0 -0.0.20161003git056315d.fc24.x86_64 to add a DC, and failing - against master. The client is unhappy: File "/home/ykaul/ovirt-system-tests/basic-suite-master/test-scenarios/002_bootstrap.py", line 98, in add_dc4 version=sdk4.types.Version(major=DC_VER_MAJ,minor=DC_VER_MIN), File "/usr/lib64/python2.7/site-packages/ovirtsdk4/services.py", line 4347, in add response = self._connection.send(request) File "/usr/lib64/python2.7/site-packages/ovirtsdk4/__init__.py", line 276, in send return self.__send(request) File "/usr/lib64/python2.7/site-packages/ovirtsdk4/__init__.py", line 298, in __send self._sso_token = self._get_access_token() File "/usr/lib64/python2.7/site-packages/ovirtsdk4/__init__.py", line 460, in _get_access_token sso_response = self._get_sso_response(self._sso_url, post_data) File "/usr/lib64/python2.7/site-packages/ovirtsdk4/__init__.py", line 498, in _get_sso_response return json.loads(body_buf.getvalue().decode('utf-8')) File "/usr/lib64/python2.7/json/__init__.py", line 339, in loads return _default_decoder.decode(s) File "/usr/lib64/python2.7/json/decoder.py", line 364, in decode obj, end = self.raw_decode(s, idx=_w(s, 0).end()) File "/usr/lib64/python2.7/json/decoder.py", line 382, in raw_decode raise ValueError("No JSON object could be decoded") ValueError: No JSON object could be decoded Surprisingly, I now can't find that RPM of this SDK in resources.ovirt.org now. I've tried with http://resources.ovirt.org/pub/ovirt-master-snapshot/rp m/fc24/x86_64/python-ovirt-engine-sdk4-4.0.0-0.1.20161004git f94eeb5.fc24.x86_64.rpm - same result. Did not see anything obvious on server or engine logs. The code: def add_dc4(api): nt.assert_true(api != None) dcs_service = api.system_service().data_centers_service() nt.assert_true( dc = dcs_service.add( sdk4.types.DataCenter( name=DC_NAME4, description='APIv4 DC', local=False, version=sdk4.types.Version(major=DC_VER_MAJ,minor=DC_VER_ MIN), ), ) ) And the api object is from: return sdk4.Connection( url=url, username=constants.ENGINE_USER, password=str(self.metadata['ovirt-engine-password']), insecure=True, debug=True, )