I see this error when open jnlp file via javaws manually:
java.lang.AssertionError: Threading violation: not AppKit thread
Is there anything I can do with it?
Once I reverted back to the Apple provided java packages, it fixed my problems.
The article for this download is:
Update: Note that for some people, the Java 7 update works with Lantronix Spiders. I can confirm that a colleague with the same model Macbook Pro has no problems using the latest Java 7 update. Another with a Macbook Air experiences the same issue, which is also resolved by rolling back.
I found that on Lantronix Spider under Console settings, change "KVM Console Deployment" from "Web Start" to "Applet" and it worked again.