I have an enterprise java application that has plenty of jars that are downloaded to the client\'s jvm cache by a jnlp file. When I start the application I get the following
I recommend you to enable tracing and logging, see here how:

And then run the application from command line.
javaws -verbose AppName.jnlp
Then you could check for clues in log and trace files stored in this path
\Documents and Settings\\Application Data\Sun\Java\Deployment\log
img source:
http://www.cisco.com/c/en/us/support/docs/security/hostscan/117097-trouble-java7-00.html