khurmi.navpreet (8/15/2013)- Check if the login is connected to the user in the database: use {db_name};exec sp_change_users_login 'Report' - Executed this command but it gave me only 2 usernames with UserID's.
The 2 usernames with the UserID's indicate that a connection between the user and the login is lost. The connection is lost due to a mismatch between the UserID's of the Login and the corresponding User. Most probably a database restore is executed or the login is deleted and re-created.
You can use the following command for each listed username to re-connect them again:
use {db_name};exec sp_change_users_login 'Auto_fix', '{username}'