Hi, I'm writing to you because I had an issue with Airflow (1.7.1.3).
I was using Celery with RabbitMQ and because of the requirements 'celery>=3.1.17', the Celery version 4.0.2 was installed in my case. I was capable of publishing tasks in the queue but when the worker read them, it output : "[WARNING/MainProcess] Received and deleted unknown message. Wrong destination?!?" (like this : https://github.com/celery/celery/issues/3675) After a bit more research, I found that Celery > 4.0 might be incompatible with librabbitmq (I am using 1.6.1) : https://github.com/celery/celery/issues/3689#issuecomment-267465309 So I uninstall Celery and reinstall it with 'celery>=3.1.17,<4.0' and now it's working like a charm. I don't know if you will be able to reproduce the problem but I wanted to share the info with you. Best regards, Franck
