BadRequest: Bad network format: missing 'uuid' (HTTP 400) in heat havana

hi usha veepuri ,
Could you please provide more details for the bug and template you used to create?

It seems you are creating an instance, and the network is missing when create the instance.

The following is an example of Instance:
heat_template_version: 2015-04-30
...
resources:
  ...
  the_resource:
    type: OS::Nova::Server
    properties:
      admin_pass: String
      availability_zone: String
      block_device_mapping: [{"snapshot_id": String, "volume_id": String, "volume_size": Integer, "device_name": String, "delete_on_termination": Boolean}, {"snapshot_id": String, "volume_id": String, "volume_size": Integer, "device_name": String, "delete_on_termination": Boolean}, ...]
      block_device_mapping_v2: [{"device_name": String, "swap_size": Integer, "disk_bus": String, "boot_index": Integer, "snapshot_id": String, "image_id": String, "volume_size": Integer, "volume_id": String, "delete_on_termination": Boolean, "device_type": String}, {"device_name": String, "swap_size": Integer, "disk_bus": String, "boot_index": Integer, "snapshot_id": String, "image_id": String, "volume_size": Integer, "volume_id": String, "delete_on_termination": Boolean, "device_type": String}, ...]
      config_drive: Boolean
      diskConfig: String
      flavor: String
      flavor_update_policy: String
      image: String
      image_update_policy: String
      key_name: String
      metadata: {...}
      name: String
      networks: [{"subnet": String, "uuid": String, "network": String, "port": String, "port_extra_properties": {"allowed_address_pairs": [{"mac_address": String, "ip_address": String}, {"mac_address": String, "ip_address": String}, ...], "admin_state_up": Boolean, "qos_policy": String, "binding:vnic_type": String, "value_specs": {...}, "port_security_enabled": Boolean, "mac_address": String}, "fixed_ip": String}, {"subnet": String, "uuid": String, "network": String, "port": String, "port_extra_properties": {"allowed_address_pairs": [{"mac_address": String, "ip_address": String}, {"mac_address": String, "ip_address": String}, ...], "admin_state_up": Boolean, "qos_policy": String, "binding:vnic_type": String, "value_specs": {...}, "port_security_enabled": Boolean, "mac_address": String}, "fixed_ip": String}, ...]
      personality: {...}
      reservation_id: String
      scheduler_hints: {...}
      security_groups: [Value, Value, ...]
      software_config_transport: String
      user_data: String
      user_data_format: String

And the definition of network is as below, you need to set an available network name or uuid for the instance.

network

Name or ID of network to create a port on.

String value expected.

Can be updated without replacement.

Value must be of type neutron.network