Error: The SOAP action specified on the message, '', does not match the HTTP SOAP Action

HI

I have a question

After an external web call an wcf application...

The server returned this error:  

<s:Text xml:lang="es-PE">The SOAP action specified on the message, '', does not match the HTTP SOAP Action, 'http://tempuri.org/IInterfacesWeb/AfiliarComercio'.</s:Text>