Syncing docker images from registry.hub.docker.com failed with PulpError PLP0000: Not Found on Red Hat Satellite 6

Issue

• Obtained following errors while syncing docker images from registry.hub.docker.com:

  pulp: celery.app.trace:ERROR: [ff3a28df] (25673-23616) Task pulp.server.managers.repo.sync.sync[ff3a28df-4d96-4eba-9cb9-e8af8772c5e0] raised 
  unexpected: IOError('Not Found',)
  Mar  9 18:44:53 vm251-165 pulp: celery.app.trace:ERROR: [ff3a28df] (25673-23616) Traceback (most recent call last):
  Mar  9 18:44:53 vm251-165 pulp: celery.app.trace:ERROR: [ff3a28df] (25673-23616)   File "/usr/lib/python2.7/site-packages/celery/app/trace.py", line
  367, 
  in trace_task
  Mar  9 18:44:53 vm251-165 pulp: celery.app.trace:ERROR: [ff3a28df] (25673-23616)     R = retval = fun(*args, **kwargs)