Cause: The SQL Server login authentication mode is not set to a hybrid authentication mode, because the authentication mode is a Windows authentication mode after the default installation, resulting in an error.
Solve: 1. Start SQL Server Enterprise Manager and select the server you want to authenticate mode. Right-click the server and select Properties in the pop-up menu, and SQL Server will pop up the property dialog. 2. Select Security Options in the Properties dialog box, select SQL Server and Windows, and then OK.
