Missing participant property during delivery

[gdchamal]

Twitter message delivery fail with this kind of error :

[mq-worker-697b466cf8-f8xrf] Traceback (most recent call last): 
[mq-worker-697b466cf8-f8xrf]   File "/srv/caliopen/src/backend/interfaces/NATS/py.client/caliopen_nats/subscribers.py", line 93, in process_raw 
[mq-worker-697b466cf8-f8xrf]     new_message = deliver.process_raw(payload['message_id']) 
[mq-worker-697b466cf8-f8xrf]   File "/srv/caliopen/src/backend/interfaces/NATS/py.client/caliopen_nats/delivery.py", line 36, in process_raw 
[mq-worker-697b466cf8-f8xrf]     message = self.qualifier.process_inbound(raw) 
[mq-worker-697b466cf8-f8xrf]   File "/srv/caliopen/src/backend/components/py.pi/caliopen_pi/qualifiers/twitter.py", line 78, in process_inbound 
[mq-worker-697b466cf8-f8xrf]     new_message) 
[mq-worker-697b466cf8-f8xrf]   File "/srv/caliopen/src/backend/components/py.pi/caliopen_pi/qualifiers/twitter.py", line 29, in lookup_discussion_sequence 
[mq-worker-697b466cf8-f8xrf]     participants = message.hash_participants 
[mq-worker-697b466cf8-f8xrf]   File "/srv/caliopen/src/backend/main/py.main/caliopen_main/message/parameters/message.py", line 62, in hash_participants 
[mq-worker-697b466cf8-f8xrf]     ids_hash = hash_participants_uri(self.participants) 
[mq-worker-697b466cf8-f8xrf]   File "/srv/caliopen/src/backend/main/py.main/caliopen_main/participant/core/participant.py", line 40, in hash_participants_uri 
[mq-worker-697b466cf8-f8xrf]     raise Exception("missing mandatory property in participant") 
[mq-worker-697b466cf8-f8xrf] Exception: missing mandatory property in participant 
[mq-worker-697b466cf8-f8xrf] ERROR:subscribers:deliver process failed for raw {u'message_id': u'956b2d1c-4aa0-4526-9d80-2db55470ec51', u'user_id': u'7559ef2c-9a9d-40f8-8ff2-3636d10d90f6', u'order': u'process_raw', u'identity_id': u'4aebb920-9e3c-4a1f-8cd7-e48e59ef4756'}: None