SRVE0209E: Writer already obtained seen using XMLAccess against WebSphere Portal v7 when SPNEGO is configured

When running: -

$ cd /opt/IBM/WebSphere/wp_profile/PortalServer/bin 
$  ./xmlaccess.sh -in /opt/IBM/WebSphere/PortalServer/doc/xml\-samples/Export.xml -out /tmp/snafu.xml -url http://portal.uk.ibm.com:10039/wps/config -user WPSAdmin -password Passw0rd

returns: -

SRVE0209E: Writer already obtained

in /tmp/snafu.xml.

This Technote, amongst others, provides a circumvention / solution to this: -

PK64013; 6.1.0.19: provide way to turn off tai authentication

http://www-01.ibm.com/support/docview.wss?uid=swg24022079

Create a new security Custom Property 

com.ibm.websphere.security.performTAIForUnprotectedURI

set to false ( the default is true ) via Security -> Global security > Custom properties.

Once we did this, and restarted WebSphere Portal, the job was done :-)