If the data source used by your visual or presentation is based on Windows Authentication or SAP Logon Tickets, then a separate panel may be presented to the user when they set up subscriptions, print jobs, and so on. They may need to supply a set of credentials to successfully submit the scheduled task.
Windows Authentication
This often occurs when the authentication method for the data source is set to "End-user" Windows Authentication. Under this model, the user running the queries is used to connect (via Kerberos token) to the data source. However, when running a batch task (offline), the user's token is not available - as such a set of their credentials is required for connectivity by the Pyramid engine.
Note: You may not need to authenticate manually if the website authenticates using Basic or Forms.
SAP Logon Tickets
Schedules can also be configured for SAP BW sources if SAP Logon Tickets is selected as the authentication method in the Admin console. In this case, you'll be prompted to enter the relevant credentials.
Note: SAP Logon Tickets are available with an Enterprise license only.