- Check for any errors in the SQL Error log - NO ERROR

- Check if the login you use still exists on the instance - DOES EXIST

- Check if the login has the correct permissions on the database - YES

- 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.