Error: Variable not found in variable substitution table

Hi,

I am getting following error in file adapter receiver communication channel.

error:Could not process due to error: com.sap.aii.adapter.file.configuration.DynamicConfigurationException: Error during variable substitution: java.text.ParseException: Variable 'file' not found in variable substitution table

<b>variable substitution values:</b>

Variable name: File

reference :payload:MT_DC_Recr,1,Target,1,Filename,1

file name scheme : %File%.txt

<b>inpu file:</b>

<?xml version="1.0" encoding="UTF-8"?>

<ns0:MT_DC_Send xmlns:ns0="http://urn:psr/ff/DC">

<Source>

<Filename>dat1</Filename>

<Record>

<Name1>123</Name1>

<Name2>abc</Name2>

<Name3>XYZ</Name3>

</Record>

</Source>

</ns0:MT_DC_Send>

Regards,

Srini