Explanation
The workbench cannot communicate with the agent computer.
User response
Try running the schedule again, using default values for all parameters and running at reduced user load levels. It is possible one agent computer is overloaded. If you can run successfully with the default values, make changes to the schedule settings or user load incrementally to determine the cause of failure.
Increase the statistics interval to 60 seconds and try running the schedule again.
Check the error log for messages that might indicate the cause of the failure. Click Window > Show View > Error Log to open the error log.