Before the Archive Viewer can be used to view archived instances, the archive database has to be created, the process execution engine must be configured to use the archive database, and instances have to be archived into the archive database.
Since ALBPM Enterprise is not configured by default to store a process instance archive, all of the above settings must be configured. This is done from the Process Administrator.
Also, the Archive Viewer itself must be running. For the Standalone edition, this is controlled from Admin Center. For the BEA WebLogic and IBM WebSphere editions this is controlled from the application server.
For more information, see the Process Administrator and Admin Center documentation.