I experienced this error and worked around it by adding the site to the Java security exception site list. On Windows this is accessed on the security tab of the Java control panel. Note that at first I added the https URL for my KVM. That was not sufficient. You must enter the http URL (I don't know if the https URL is necessary. I left that exception configured.)
Since Oracle released the latest Java version I have had to add these exceptions for every Java based console app that I use. Ugh!