Customers had access to run the report for all users in 9.1SP1 but after upgrading to 9.1SP5, it is observed that the username is mandatory field and report can not be run for all users.
How to find all users in the exception list for today in AA 9.1SP5?
Advanced Authentication
Release: 9.1SP5
Prior to 9.1SP3 release reports returned information for all users by default. For security purposes, and to reduce the report-generation workload, 9.1SP3 release of Advanced Authentication adds the ability to restrict information returned in reports to a single user. This release adds a mandatory User Name field to the report generation page. The report only returns information for the user whose name the administrator enters in this field.
Screen shot below for this setting in Admin console-