We have been processing a Tableau Workbook using a data extract and refreshing that extract daily. The extract connects to a SQL Server 2005 backend using AD login and has worked great until today. Now Tableau seems to be passing the NT ANONYMOUS credentials to the server instead of the AD credentials. We are working Tableau 6.1 and have tried log off/on and re-starting the machine. This is happening on multiple machines running Windows XP.