When you are running any version of Operations (Ops) Manager 1.11.x or 1.12.0, you will see the following error when trying to "Apply Changes".
Due to hardening that was performed on the Ops Manager VM, access to the `ping`
command by the Ops Manager UI is no longer allowed. This causes the ICMP check to always fail on Ops Manager. This failure happens regardless of the network and its support for ICMP.
Workaround:
Pivotal will investigate further and fix this issue in a future release.