@dplatten - are you able to shed any light on the celery and amqp version compatibility?
We also need to change the ssettings.py from amqp which seems to be long since deprecated to CELERY_RESULT_BACKEND = 'rpc://' - I don't know if there are any consequences - presumably we just change the setting and restart Celery?
Also, the CELERYD_PREFETCH_MULTIPLIER = 1 setting and I notice you are using concurrency of 1 - is this a problem? Does it not mean that everything is always waiting in a queue, particularly if you have one long running task?
On my Windows Server 2012 install I am running celery 4.0.0, seemingly without problem.
I am using this with the following celery settings in settings.py (concurrency is 4 in the settings and in the celery command). Note that CELERY_RESULT_BACKEND is set to rpc, rather than rpc:// - I don't know if this matters, but it appears to work as it is.