File copy job error

Running a file copy job and it getting this on the client

<event date="Mar 25 17:22:43" severity="1" hostName="XXXXXXX" source="Copy File Task" module="ClientCopyFile.dll" process="AeXNSAgent.exe" pid="1556" thread="3740" tickCount="4165843"><![CDATA[Command  to get N/W Credentials failed.]]></event>

all other jobs are working OK. anyone got any ideas.

Joe.