Barrier Requests throwing errors

Barrier requests have started throng errors. Any ideas? Thanks.

2014-08-08 06:47:32.972 EDT [md-sal-binding-notification-39] ERROR o.o.c.sal.binding.impl.NotifyTask - Unhandled exception thrown by listener: org.opendaylight.controller.sal.compatibility.InventoryAndReadAdapter$$Broker$ListenerInvoker@43d5f0c
java.lang.IllegalArgumentException: null
at com.google.common.base.Preconditions.checkArgument(Preconditions.java:76) ~[na:na]
at org.opendaylight.ovsdb.openstack.netvirt.impl.ProviderNetworkManagerImpl.getProvider(ProviderNetworkManagerImpl.java:40) ~[na:na]
at org.opendaylight.ovsdb.openstack.netvirt.SouthboundHandler.notifyNode(SouthboundHandler.java:401) ~[na:na]
at org.opendaylight.controller.switchmanager.internal.SwitchManager.notifyNode(SwitchManager.java:1827) ~[na:na]
at org.opendaylight.controller.switchmanager.internal.SwitchManager.addNode(SwitchManager.java:1049) ~[na:na]
at org.opendaylight.controller.switchmanager.internal.SwitchManager.updateNode(SwitchManager.java:1150) ~[na:na]
at org.opendaylight.controller.sal.implementation.internal.Inventory.updateNode(Inventory.java:115) ~[na:na]
at org.opendaylight.controller.sal.compatibility.InventoryAndReadAdapter.publishNodeUpdate(InventoryAndReadAdapter.java:728) ~[na:na]
at org.opendaylight.controller.sal.compatibility.InventoryAndReadAdapter.onNodeUpdated(InventoryAndReadAdapter.java:463) ~[na:na]
at org.opendaylight.controller.sal.compatibility.InventoryAndReadAdapter$$Broker$ListenerInvoker.onNotification(InventoryAndReadAdapter$$Broker$ListenerInvoker.java) ~[na:na]
at org.opendaylight.controller.sal.binding.impl.AbstractNotificationListenerRegistration.notify(AbstractNotificationListenerRegistration.java:38) ~[na:na]
at org.opendaylight.controller.sal.binding.impl.NotifyTask.run(NotifyTask.java:42) ~[na:na]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [na:1.7.0_60]
at java.util.concurrent.FutureTask.run(FutureTask.java:262) [na:1.7.0_60]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [na:1.7.0_60]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [na:1.7.0_60]
at java.lang.Thread.run(Thread.java:745) [na:1.7.0_60]
2014-08-08 06:47:33.105 EDT [nioEventLoopGroup-13-3] WARN o.o.o.p.i.c.ResponseExpectedRpcListener - Request for RpcResultKey [xid=14, outputClazz=org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.BarrierOutput] did not receive a response