The response is not in JSON

Hi Team Pymisp,

I'm trying to send events to Azure Sentinel but receive the error Unknown error: the response is not in JSON.

Config.py content excluding graph_auth

targetProduct = 'Azure Sentinel'
misp_event_filters = []
action = 'alert'
passiveOnly = False
days_to_expire = 30
misp_key = 'XXXXXXXXXXXXXX'
misp_domain = 'XXXXXXXXXXXXXXXXX'
misp_verifycert = False

Error Log

(mispToSentinel) XXX@XXX:~/mispToSentinel/security-api-solutions/Samples/MISP$ sudo python3 script.py
fetching & parsing data from misp...
Unknown error: the response is not in JSON.
Something is broken server-side, please send us everything that follows (careful with the auth key):
Request headers:
{'User-Agent': 'PyMISP 2.4.144 - Python 3.6', 'Accept-Encoding': 'gzip, deflate', 'Accept': 'application/json', 'Connection': 'keep-alive', 'Cookie': 'MISP-2906f9eb-3ab4-4838-8a5b-6c42305b4b8c=r4vcgpirqpcbve8onbfhoroi6n', 'Content-Length': '265', 'Authorization': '', 'content-type': 'application/json'}
Request body:
{"returnFormat": "json", "withAttachments": 0, "metadata": 0, "enforceWarninglist": 0, "includeEventUuid": 0, "includeEventTags": 0, "sgReferenceOnly": 0, "includeContext": 0, "headerless": 0, "includeSightings": 0, "includeDecayScore": 0, "includeCorrelations": 0}
Response (if any):

Traceback (most recent call last):
  File "script.py", line 100, in <module>
    main()
  File "script.py", line 69, in main
    events = _get_events()
  File "script.py", line 16, in _get_events
    return [event['Event'] for event in misp.search(controller='events', return_format='json')]
  File "/usr/local/lib/python3.6/dist-packages/pymisp/api.py", line 2473, in search
    normalized_response = self._check_json_response(response)
  File "/usr/local/lib/python3.6/dist-packages/pymisp/api.py", line 3400, in _check_json_response
    r = self._check_response(response, expect_json=True)
  File "/usr/local/lib/python3.6/dist-packages/pymisp/api.py", line 3417, in _check_response
    raise MISPServerError(f'Error code 500:\n{response.text}')
pymisp.exceptions.MISPServerError: Error code 500:

Can you help?

Start with script.py at _get_events and trace the call into pymisp/api.py, especially _check_json_response and _check_response. Reproduce the request and inspect the server response and relevant MISP logs; done means identifying why the events request returns HTTP 500 with no JSON and documenting a confirmed cause or fix.