contrail ui get error An unexpected error occurred

[YuYang]

i install contrail controller in vm, when i open contrail ui will get the error:
error code:500
error msg:An unexpected error occurred!

root@Contrail-Controller:~# contrail-version
Package Version Build-ID | Repo | Package Name
-------------------------------------- ------------------------------ ----------------------------------
contrail-analytics 4.0.0.0-20 20
contrail-config 4.0.0.0-20 20
contrail-config-vmware 4.0.0.0-20 20
contrail-control 4.0.0.0-20 20
contrail-database-common 4.0.0.0-20 20
contrail-dns 4.0.0.0-20 20
contrail-docs 4.0.0.0-20 20
contrail-f5 4.0.0.0-20 20
contrail-fabric-utils 4.0.0.0-20 20
contrail-install-packages 4.0.0.0-20~vcenter 20
contrail-install-vcenter-plugin 4.0.0.0-06052017 20
contrail-lib 4.0.0.0-20 20
contrail-nodemgr 4.0.0.0-20 20
contrail-openstack-analytics 4.0.0.0-20 20
contrail-openstack-control 4.0.0.0-20 20
contrail-openstack-database 4.0.0.0-20 20
contrail-openstack-webui 4.0.0.0-20 20
contrail-setup 4.0.0.0-20 20
contrail-utils 4.0.0.0-20 20
contrail-vmware-config 4.0.0.0-20 20
contrail-web-controller 4.0.0.0-20 20
contrail-web-core 4.0.0.0-20 20
python-contrail 4.0.0.0-20 20