SQL Mixed Authentication mode

So I have a database with mixed authentication mode. I have a piece of software that connects to it. I was using this software since about January with no problems. I add a table to this database. When I try to access this table by a query I get Log In Failed. The log in is from an untrusted d开发者_开发技巧omain This is odd because my connection string is connectionString="Data Source=JOET-HP\SQLEXPRESS;Initial Catalog=AmazonProShip; User Id= Shipper; Password=Shipping1; Has any encounter this and found a solution?

Did you recently apply SQL Server updates (directly, or indirectly through Windows update)? There is a known issue where mixed mode occasionally gets changed to Windows auth only.

If you have Management Studio (and maybe Express has this functionality as well), you can check / update it by right-clicking the server name in Object Explorer, selecting Properties, moving to Security - it's the first radio option.

If you don't have Management Studio, you need to find the right LoginMode registry subkey for your instance (probably HKEY_LOCAL_MACHINE > SOFTWARE > Microsoft > Microsoft SQL Server > MSSQL10.SQLEXPRESS > MSSQLServer) and change the value to 2 (if it is not already 2, stop SQL Server first, change the value, close the registry, and restart SQL Server).