Here is possibly actual error from nova-api logs: 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi [req-f31aa7c0-4954-4f13-81fb-8e1484900ec1 640ec55b7aa04b8ab260838c568ac7f9 eb3802b4c9a94aa99b40144702de9ef7 - default default] Unexpected exception in API method: AttributeError: 'NoneType' object has no attribute 'uuid' 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi Traceback (most recent call last): 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/objects/instance.py", line 655, in destroy 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi hard_delete=hard_delete) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/db/api.py", line 549, in instance_destroy 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi hard_delete=hard_delete) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/db/sqlalchemy/api.py", line 179, in wrapper 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi return f(*args, **kwargs) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/oslo_db/api.py", line 154, in wrapper 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi ectxt.value = e.inner_exc 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/oslo_utils/excutils.py", line 220, in __exit__ 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi self.force_reraise() 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/oslo_utils/excutils.py", line 196, in force_reraise 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi six.reraise(self.type_, self.value, self.tb) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/six.py", line 703, in reraise 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi raise value 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/oslo_db/api.py", line 142, in wrapper 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi return f(*args, **kwargs) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/db/sqlalchemy/api.py", line 222, in wrapped 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi return f(context, *args, **kwargs) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/db/sqlalchemy/api.py", line 1166, in instance_destroy 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi raise exception.ConstraintNotMet() 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi nova.exception.ConstraintNotMet: Constraint not met. 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi During handling of the above exception, another exception occurred: 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi Traceback (most recent call last): 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/compute/api.py", line 2193, in _delete 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi if self._delete_while_booting(context, instance): 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/compute/api.py", line 2135, in _delete_while_booting 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi instance.destroy() 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/oslo_versionedobjects/base.py", line 226, in wrapper 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi return fn(self, *args, **kwargs) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/objects/instance.py", line 659, in destroy 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi reason='host changed') 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi nova.exception.ObjectActionError: Object action destroy failed because: host changed 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi During handling of the above exception, another exception occurred: 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi Traceback (most recent call last): 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/api/openstack/wsgi.py", line 671, in wrapped 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi return f(*args, **kwargs) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/api/openstack/compute/servers.py", line 996, in delete 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi return f(*args, **kwargs) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/api/openstack/compute/servers.py", line 996, in delete 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi self._delete(req.environ['nova.context'], req, id) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/api/openstack/compute/servers.py", line 803, in _delete 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi self.compute_api.delete(context, instance) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/compute/api.py", line 227, in inner 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi return function(self, context, instance, *args, **kwargs) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/compute/api.py", line 154, in inner 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi return f(self, context, instance, *args, **kw) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/compute/api.py", line 2515, in delete 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi self._delete_instance(context, instance) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/compute/api.py", line 2507, in _delete_instance 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi task_state=task_states.DELETING) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/compute/api.py", line 2230, in _delete 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi self._local_delete_cleanup(context, instance) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/compute/api.py", line 2147, in _local_delete_cleanup 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi context, instance.uuid) 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi AttributeError: 'NoneType' object has no attribute 'uuid' 2020-08-24 18:00:07.553 17 ERROR nova.api.openstack.wsgi 2020-08-24 18:00:07.560 17 INFO nova.api.openstack.wsgi [req-f31aa7c0-4954-4f13-81fb-8e1484900ec1 640ec55b7aa04b8ab260838c568ac7f9 eb3802b4c9a94aa99b40144702de9ef7 - default default] HTTP exception thrown: Unexpected API Error. Please report this at http://bugs.launchpad.net/nova/ and attach the Nova API log if possible. 2020-08-24 18:00:07.562 17 DEBUG nova.api.openstack.wsgi [req-f31aa7c0-4954-4f13-81fb-8e1484900ec1 640ec55b7aa04b8ab260838c568ac7f9 eb3802b4c9a94aa99b40144702de9ef7 - default default] Returning 500 to user: Unexpected API Error. Please report this at http://bugs.launchpad.net/nova/ and attach the Nova API log if possible.