Error VC(Visual Composer)

Dear Experts.

I am working with SAP NW 7.4 However with execute the following link for migrate customer development(file PAR), the system genera a dump(Log portal)

http://hostname:port/irj/servlet/prt/portal/prtroot/com.sap.portal.runtime.system.console.ArchiveUploader

Invalid Response code (401). Server [http://hostname:50013/SAPControl.cgi] returned message [Unauthorized]. Http proxy info:  none
[EXCEPTION]
com.sap.engine.services.webservices.espbase.client.bindings.exceptions.TransportBindingException: Invalid Response code (401). Server [http://hostname:50013/SAPControl.cgi] returned message [Unauthorized]. Http proxy info:  none

What is the cause of this error?

Thanks

Regards