...

The below troubleshooting hints are intended for users operating a Standalone Controller, the steps explained are not required for users operating a Controller Cluster.

Troubleshooting

The Controller is the component in JS7 that holds job-related configurations and that orchestrates Agents. The outage of a Controller instance does not prevent the execution of workflows with jobs running on a single Agent. However, it affects the execution of workflows that include jobs running on a number of Agents as switching of Agents during workflow execution is performed by the Controller. 

A Controller instance outage can be handled either by resolving the issue with the current Controller instance, e.g. by restarting or by relocating the ./state directory to a new Controller instance. This directory holds the Controller instance's journal. To relocate a Controller instance copy the journal files to the new Controller instance. Refer to the JS7 - Moving Components - Relocating a Controller article for the steps to apply.See JS7 - Troubleshooting - How to troubleshoot the outage of a Controller