SSIS get issue as soon as I assign variable to Excel Source task

I have a package where I am reading from excel and sending data to database, everything is working fine if I have not assigned any variable. But if I assign a variable value as expression to the excel connection manager then I am facing below issue. Kindly let me know how to resolve this issue.

TITLE: Package Validation Error
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Package Validation Error

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ADDITIONAL INFORMATION:

Error at Data Flow Task [Excel Source [2]]: 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]: Excel Source 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 Perdiem_general_input [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: "Failure creating file.".

 (Microsoft.DataTransformationServices.VsIntegration)

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BUTTONS:

OK
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