The process engine status is in the Grey (Cannot determine engine status).
The process engine is not down if it is in the Gray status.
The process engine will typically go from Gray to Yellow (Running) status.
The process engine shows the current and past history of deployments. Green will never display as only colors to display are (gray,yellow,red).
So long as the process engine is not in the Red status, and is in the Gray or Yellow statuses, the process engine is up and running.
If it is in the Gray status indefinitely, and processes and jobs are not running, the BG may be hung. In this case restart the BG service and review bg-ca and bg-system logs.
Note: Only restart BG if your processes and jobs aren't running. The icon itself is not a sufficient indication for a bg restart as it may simply not be updating due to a multicast/network issue.
Another method to check if the process engine is active, is to check either the