Error deploying JSP with WorkBench

I have an error when deploy my JSP with WorkBench, below is the error
message:

Deploy Cmd : D:\SilverStream37\bin\SilverCmd DeployWAR goatstudio lucent
F:\work\helloworld\helloworld.war -f
F:\work\helloworld\UntitledWARDeplPlan.xml -o -v 3 -i
Error loading meta data from 'F:\work\helloworld\UntitledWARDeplPlan.xml',
An error occurred while trying to parse the XML file.

Error: Stopping after fatal error: File "file:///d:/Program
Files/SilverStream/eXtendWorkbench/bin/deploy-war_2_2.dtd" not found.
(org.xml.sax.SAXException)
You must specify a server, database, WAR file, and -f deploymentPlanFile
arguments.


Anyone know what is the possible cause?

Thanks.

regards,
vic