After an upgrade to version 11.x, Reporter GUI is not accessible. You're getting 401 HTTP error when accessing GUI:
The GUI "not working" is expected behavior on Reporter version 11.x where device becomes a 'headless' state. Please check the following notes:
About Reporter 11.0.1.1
The Reporter 11.0.1.1 and later has no web-based user interface. All administration must be done in the device's Reporter Admin Console (RPAC) accessed from within Management Center.
From Release Notes:
Reporter Admin Console 1.2 (Full Administration)
Reporter 11.0.1.1 includes support for Reporter Admin Console (RPAC) 1.2, which contains the full set of administrative functionality. After initial configuration, users should be able to fully manage Reporter from inside Management Center.
To launch RPAC, you must first download the RPAC software package (from the Broadcom support site) to Management Center (MC).
In order to manage and use Reporter 11, connect via MC and/or RPAC. More information below:
1. Add a Reporter
https://techdocs.broadcom.com/us/en/symantec-security-software/web-and-network-security/management-center/3-2/add_monitor_devices/add_device/Add-a-Reporter.html
2. Reporter Admin Console (RPAC) Compatibility Information
https://techdocs.broadcom.com/us/en/symantec-security-software/web-and-network-security/management-center/3-2/add_monitor_devices/launch-sg-admin-console/Reporter-Admin-Console-Compatibility-Information.html