Network admins at my company did something...took away privileges and add others and now my report interface no longer is able to read the user accessing the reports. This is important because there is code that is dependent upon the user that logs in. I need help trying to figure out what went wrong so I can fix it because they don't think they did anything wrong. Where do I start?

User.Identity.Name used to return the username logging into the application. Now it returns nothing, so certain users are unable to access their special reports.

Help?!?!