It can be helpful to check the status of an instance, this will help you see where the instance is in the process. 

You can check the status of the instance in the Instance Overview by clicking on the tab with the application name in the right-hand corner. In the example below, the name of the application, and therefore the name of the tab, is Claims request. 

The video below shows how you can locate the Process Model view of an instance from the Instance Overview and use the token trail to track the process of an instance.

Yellow - Waiting

Red- Error

Grey - Completed or Stuck

The most common reason a grey token will appear is because it has been split or merged in a gateway. 

For example, when a token reaches a parallel gateway, the original token gets consumed, and a new token is created for each outgoing sequence flow.

Errors

If there is an error, the error log will indicate what is wrong. You can set up email notifications for Error Messages to be sent to the configurator or admin to identify the error. Read more about the Event Log here. 

To troubleshoot errors, begin by reviewing the error message. You can also look at the Data Id and Field name, it could be that there is a simple mistake in the expression. 

Note: Always make sure to test your process flow or form before deploying changes of logic in the flow or form.