Cluster installation fails with Error "Unable to restart service atomic-openshift-node" in Openshift Container Platform 3

Issue

Running the advanced installer fails with the following error:

RUNNING HANDLER [openshift_node : restart node] **********************************************************************************************************************************************
Friday 01 June 2018  10:18:13 -0600 (0:00:00.057)       0:24:10.292 *********** 
FAILED - RETRYING: restart node (3 retries left).
...

fatal: [node1.example.com]: FAILED! => {"attempts": 3, "changed": false, "msg": "Unable to restart service atomic-openshift-node: Job for atomic-openshift-node.service failed because the control process exited with error code. See \"systemctl status atomic-openshift-node.service\" and \"journalctl -xe\" for details.\n"}

Examining log entries on a master shows errors similar to these:

Jun 01 11:30:17 trewq0101 atomic-openshift-node[20024]: F0101 11:30:17.608671   20024 network.go:46] SDN node startup failed: failed to validate network configuration: master has not created a default cluster network, network plugin "redhat/openshift-ovs-subnet" can not start"
...

Jun 01 12:03:31 trewq0101 atomic-openshift-master-controllers[42465]: F0101 12:03:31.738780   42465 start_master.go:655] Error starting "openshift.io/sdn" (failed to start SDN plugin controller: ClusterNetwork "default" is invalid: clusterNetworks[0].hostSubnetLength: Invalid value: 0x9: subnet length is too large for clusterNetwork )