This error usually occurs when Right Click Tools is not able to ping the computer before running an action. By default Right Click Tools will attempt to ping a computer before running an action in an effort to speed up actions against large groups of computers. This would verify if a computer is online and after verified run the action, rather than trying to run an action against a computer that is not on and may take some time before erroring out.
Information on how to configure your environment for ICMP Echo (ping response) is located here: Enabling ICMP Echo in your environment
Right Click Tools can also be configured to disable this behavior. In Standalone installations the “Ping Computer Before Running Tools” box can be found under “general” in the Configure Recast RCT application.
With a recast Management Server this setting can be found as a “Global Setting” Plugin named “PingComputerBeforeRunningTools”.