12.1.0.2 root script fails to start ora.ctssd if nodes name length are not the same (Doc ID 1918426.1)
The bug is fixed in 12.1.0.2 GI PSU 1 and 12.2, the solution is to apply 12.1.0.2 GI PSU before executing root script (root.sh or rootupgrade.sh)
I assume this is for all platforms – the doc id does not state which platforms
What is ora.ctssd – Cluster Time Synchronization Service Daemon (ctssd)