Node update failing

After servicechain creation, node update is failing with following error :
update failed (client error): External Policy e3ea27fb-dad6-4ebc-9a42-172d9b264fbe could not be found

Following are the corresponding logs :

2016-04-25 05:23:21.702 974 DEBUG gbpservice.neutron.db.servicechain_db [req-0f1893d9-0357-432b-8489-c0bf06f6e995 neutron -] gbpservice.neutron.services.servicechain.plugins.ncp.plugin.NodeCompositionPlugin method update_servicechain_node called with arguments (<neutron.context.Context object at 0x7feb1b599210>, u'7d97ac67-381e-470d-97a6-f76953120af8', {u'servicechain_node': {u'config': u'{"heat_template_version": "2013-05-23", "description": "Template to deploy firewall", "resources": {"sc_firewall_rule3": {"type": "OS::Neutron::FirewallRule", "properties": {"action": "allow", "destination_port": "23", "protocol": "tcp", "name": "Rule_3"}}, "sc_firewall_rule2": {"type": "OS::Neutron::FirewallRule", "properties": {"action": "allow", "protocol": "icmp", "name": "Rule_2"}}, "sc_firewall_rule1": {"type": "OS::Neutron::FirewallRule", "properties": {"action": "allow", "protocol": "udp", "name": "Rule_1"}}, "sc_firewall_rule4": {"type": "OS::Neutron::FirewallRule", "properties": {"action": "allow", "destination_port": "80", "protocol": "tcp", "name": "Rule_4"}}, "sc_firewall_policy": {"type": "OS::Neutron::FirewallPolicy", "properties": {"name": "", "firewall_rules": [{"get_resource": "sc_firewall_rule1"}, {"get_resource": "sc_firewall_rule2"}, {"get_resource": "sc_firewall_rule3"}, {"get_resource": "sc_firewall_rule4"}]}}, "sc_firewall": {"type": "OS::Neutron::Firewall", "properties": {"firewall_policy_id": {"get_resource": "sc_firewall_policy"}, "description": "", "name": "serviceVM_infra_FW"}}}}'}}) {} wrapper /usr/local/lib/python2.7/dist-packages/oslo_log/helpers.py:45
2016-04-25 05:23:21.725 974 DEBUG gbpservice.neutron.db.servicechain_db [req-0f1893d9-0357-432b-8489-c0bf06f6e995 neutron -] gbpservice.neutron.services.servicechain.plugins.ncp.plugin.NodeCompositionPlugin method get_service_profiles called with arguments (<neutron.context.Context object at 0x7feb1b599210>,) {'filters': {'id': [u'2ec6719a-9aa6-4800-89bd-ee55f30fad6b']}} wrapper /usr/local/lib/python2.7/dist-packages/oslo_log/helpers.py:45
2016-04-25 05:23:21.730 974 DEBUG gbpservice.neutron.db.servicechain_db [req-0f1893d9-0357-432b-8489-c0bf06f6e995 neutron -] gbpservice.neutron.services.servicechain.plugins.ncp.plugin.NodeCompositionPlugin method get_servicechain_specs called with arguments (<neutron.context.Context object at 0x7feb1b5994d0>, {'id': [u'6df62c59-d615-4c53-b8a2-7bd2f0358587']}) {} wrapper /usr/local/lib/python2.7/dist-packages/oslo_log/helpers.py:45
2016-04-25 05:23:21.732 974 DEBUG gbpservice.neutron.db.servicechain_db [req-0f1893d9-0357-432b-8489-c0bf06f6e995 neutron -] gbpservice.neutron.services.servicechain.plugins.ncp.plugin.NodeCompositionPlugin method get_servicechain_instances called with arguments (<neutron.context.Context object at 0x7feb1b5994d0>, {'id': [u'47fa5e04-dfab-4243-91b9-731a85cf6739', u'4c2b8963-e1cc-4ca0-aea1-ce327b942ad4', u'8b1f4266-1ad0-4341-abdb-199ece751a64', u'c2101519-8ce1-49e3-b26e-4d0414d4dc3b']}) {} wrapper /usr/local/lib/python2.7/dist-packages/oslo_log/helpers.py:45

2016-04-25 05:23:21.743 974 DEBUG gbpservice.neutron.db.servicechain_db [req-0f1893d9-0357-432b-8489-c0bf06f6e995 neutron -] gbpservice.neutron.services.servicechain.plugins.ncp.plugin.NodeCompositionPlugin method get_servicechain_specs called with arguments (<neutron.context.Context object at 0x7feb1c0db6d0>,) {'filters': {'id': [u'6df62c59-d615-4c53-b8a2-7bd2f0358587']}} wrapper /usr/local/lib/python2.7/dist-packages/oslo_log/helpers.py:45
2016-04-25 05:23:21.746 974 DEBUG gbpservice.neutron.db.grouppolicy.group_policy_db [req-0f1893d9-0357-432b-8489-c0bf06f6e995 neutron -] gbpservice.neutron.services.grouppolicy.plugin.GroupPolicyPlugin method get_policy_target_groups called with arguments (<neutron.context.Context object at 0x7feb1c0db6d0>, {'id': [u'e3ea27fb-dad6-4ebc-9a42-172d9b264fbe']}, None, None, None, None, False) {} wrapper /usr/local/lib/python2.7/dist-packages/oslo_log/helpers.py:45
2016-04-25 05:23:21.748 974 DEBUG gbpservice.neutron.db.grouppolicy.group_policy_db [req-0f1893d9-0357-432b-8489-c0bf06f6e995 neutron -] gbpservice.neutron.services.grouppolicy.plugin.GroupPolicyPlugin method get_external_policy called with arguments (<neutron.context.Context object at 0x7feb1c0db6d0>, u'e3ea27fb-dad6-4ebc-9a42-172d9b264fbe', None) {} wrapper /usr/local/lib/python2.7/dist-packages/oslo_log/helpers.py:45

2016-04-25 05:23:21.783 974 INFO neutron.api.v2.resource [req-0f1893d9-0357-432b-8489-c0bf06f6e995 neutron -] update failed (client error): External Policy e3ea27fb-dad6-4ebc-9a42-172d9b264fbe could not be found
2016-04-25 05:23:21.784 974 INFO neutron.wsgi [req-0f1893d9-0357-432b-8489-c0bf06f6e995 neutron -] 192.168.100.105 - - [25/Apr/2016 05:23:21] "PUT /v2.0/servicechain/servicechain_nodes/7d97ac67-381e-470d-97a6-f76953120af8.json HTTP/1.1" 404 373 0.234357