Loading Excel sources to sql server table issues when I close my Excel sources

While I am trying to load Excel sources data into a SQL Server Table, it is throwing the following error...but when I opened all the sources that I am going to load into the destination then my SSIS package is successfully loading to destination. So here Execution fails when all my sources if not opened. Can any one of you resolve my problem?

TITLE: Package Validation Error

Package Validation Error

ADDITIONAL INFORMATION:

Error at Data Flow Task [Excel Source [1]]: SSIS Error Code DTS_E_CANNOTACQUIRECONNECTIONFROMCONNECTIONMANAGER.

The AcquireConnection method call to the connection manager "Excel Connection Manager" failed with error code 0xC0202009.

;There may be error messages posted before this with more information on why the AcquireConnection method call failed.Error at Data Flow Task [SSIS.Pipeline]:

component "Excel Source" (1) failed validation and returned error code 0xC020801C.Error at Data Flow Task [SSIS.Pipeline]:

One or more component failed validation.Error at Data Flow Task:

There were errors during task validation:

Error at Eco P and L [Connection manager "Excel Connection Manager"]:

SSIS Error Code DTS_E_OLEDBERROR. ;

An OLE DB error has occurred.

Error code: 0x80004005.

An OLE DB record is available. ;

Source: "Microsoft JET Database Engine" ;

Hresult: 0x80004005 ;

Description: "Could not decrypt file.".;

(Microsoft.DataTransformationServices.VsIntegration)

I got this error too. It turns out my excel file was protected. If I go to the "Review" tab and click on "Unprotect Sheet", then I could import the excel file.