I got the same error on my Firefox install (ver 12) on Windows 7. What
I found is that when I changed the jnlp file to dns name, I received a
prompt for the certificate, which I did not for the ip address. I did
not look at log files yet, but my guess is, that it was failing on the
certificate, as I never received a prompt for it.

Thank you very much sharfuddin for posting this information, it helped

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