The ProxySG appliance does not accept valid built-in administrator credentials in the Management Console or SSH, even if you change the password and try with the new password. Event logs report the following errors:
"Attempted administrator login from unauthorized source: x.x.x.x, user 'admin'"
The credentials work in the serial console.
The issue is caused by console access control list (ACL). An ACL is enforced only when console credentials are used to access either the CLI or the Management Console, or when an SSH with RSA authentication connection is attempted.
Log in to the appliance using the serial console and enter the CLI:
#show advanced-url /cli/show/configuration
If the output displays the following, the appliance has been configured to limit access to the Management Console and CLI through the console ACL: