UnicodeDecodeError: 'ascii' codec can't decode byte 0xe6 in position 0: ordinal not in range(128)

2017-03-16 11:23:29.601 1238 ERROR nova.compute.manager [instance: 3f195047-250a-4eb5-8da0-63bea6e2672c] Traceback (most recent call last):
2017-03-16 11:23:29.601 1238 ERROR nova.compute.manager [instance: 3f195047-250a-4eb5-8da0-63bea6e2672c]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1905, in _do_build_and_run_instance
2017-03-16 11:23:29.601 1238 ERROR nova.compute.manager [instance: 3f195047-250a-4eb5-8da0-63bea6e2672c]     filter_properties)
2017-03-16 11:23:29.601 1238 ERROR nova.compute.manager [instance: 3f195047-250a-4eb5-8da0-63bea6e2672c]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 2057, in _build_and_run_instance
2017-03-16 11:23:29.601 1238 ERROR nova.compute.manager [instance: 3f195047-250a-4eb5-8da0-63bea6e2672c]     instance_uuid=instance.uuid, reason=six.text_type(e))
2017-03-16 11:23:29.601 1238 ERROR nova.compute.manager [instance: 3f195047-250a-4eb5-8da0-63bea6e2672c] UnicodeDecodeError: 'ascii' codec can't decode byte 0xe6 in position 0: ordinal not in range(128)
2017-03-16 11:23:29.601 1238 ERROR nova.compute.manager [instance: 3f195047-250a-4eb5-8da0-63bea6e2672c]