The Stranded Activities view, which can be accessed via the Control Center perspective launch panel, displays activities and default case activities that are stranded because their performers have been invalidated, for example like in the following cases:
carnot.properties file.
If set to true, activities assigned to an invalid user are listed in the Stranded Activities view.
If set to false, an exception occurs in that case, which is the default behavior.
Figure: Stranded Activities View
In the Stranded Activities table, you can review and delegate the stranded activities to other participants.
For a detailed description on the columns and functionality of the activity table, refer to chapter Working with Activity Tables.
The following actions are available in the Actions column:
To delegate the selected activities to the default performer,
click the Delegate to Default Performer
icon.
For default case
activities, the Delegate to Default Performer icon is disabled.
Note that this icon is displayed only in Stranded Activities view.
A confirmation dialog opens to confirm the delegation.

Figure: Delegate to Default Performer Confirmation.
If you select more than one rows and the selected rows contain activities and default case activities to be delegated to the default performer, the following error message is displayed:

Figure: Delegate to the Default Performer - Activities and Default Case Activities
This example explains the delegation of stranded activities to the default performer. Make sure that the Delegate to Default Performer property is set for the activity. For details about this property in the Eclipse modeler, please refer to section Optionally add an Option to send Activities to the Default Performers Worklist of chapter Working With Activity Event Handlers in the Eclipse Modeling Guide. Optionally add an Option to send Activities to the Default Performers Worklist of chapter Working With Activity Event Handlers in the Eclipse Modeling Guide. For details about this property in the Modeling perspective, please refer to section Delegating to the Default Performers Worklist of the chapter Specifying Activity Properties in the Business Process Modeling Handbook.

Figure: Drag and drop User on Role 1

Figure: Invalidate the User

Figure: Delegate Activities

Figure: Stranded Activities Alert

Figure: Confirm - Delegate to Default Performer
For details on participants and users in the Eclipse modeler and the Modeling perspective, please refer to chapter Modeling the Organizational Structure in the Eclipse Modeling Guide and chapter Modeling the Organizational Structure in the Business Process Modeling Handbook respectively.