The following exception was observed in karaf logs during L3VPN creation.

2018-07-17T18:07:19,104 | ERROR | org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.bgpvpns.rev150903.bgpvpns.attributes.bgpvpns.Bgpvpn_AsyncDataTreeChangeListenerBase-DataTreeChangeHandler-0 | NeutronBgpvpnChangeListener | 352 - org.opendaylight.netvirt.neutronvpn-impl - 0.7.0.SNAPSHOT | Creation of BGPVPN d06ff78e-e093-429b-b281-3ae28ebd9a1e failed
java.lang.Exception: [Failed to associate networks with VPN d06ff78e-e093-429b-b281-3ae28ebd9a1e as given networks list is empty]
at org.opendaylight.netvirt.neutronvpn.NeutronvpnManager.createVpn(NeutronvpnManager.java:1205) [352:org.opendaylight.netvirt.neutronvpn-impl:0.7.0.SNAPSHOT]
at org.opendaylight.netvirt.neutronvpn.NeutronBgpvpnChangeListener.add(NeutronBgpvpnChangeListener.java:153) [352:org.opendaylight.netvirt.neutronvpn-impl:0.7.0.SNAPSHOT]
at org.opendaylight.netvirt.neutronvpn.NeutronBgpvpnChangeListener.add(NeutronBgpvpnChangeListener.java:44) [352:org.opendaylight.netvirt.neutronvpn-impl:0.7.0.SNAPSHOT]
at org.opendaylight.genius.datastoreutils.AsyncDataTreeChangeListenerBase$DataTreeChangeHandler.run(AsyncDataTreeChangeListenerBase.java:171) [255:org.opendaylight.genius.mdsalutil-api:0.5.0.SNAPSHOT]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:?]
at java.lang.Thread.run(Thread.java:748) [?:?]