连接到SSRS中的数据源时出错

我正在尝试连接到Datasource,但收到此错误:

An error occurred during local report processing. 
An error has occurred during report processing. 
Cannot create a connection to data source 'PO'.
You have specified integrated security or credentials in the connection string for the data source, but the data source is configured to use a different credential type. To use the values in the connection string, you must configure the unattended report processing account for the report server.

知道如何解决这个问题吗？

谢谢Aruna

看起来忘记了密码,如果是嵌入式数据源>右键单击数据源,然后转到属性>凭据.

如果是共享数据源,请转到共享数据源,右键单击共享数据源并单击"打开",然后单击凭据并再次输入凭据.