So the latest Java update Version 7 Update 51 again contains new updates and again more security fixes. Alas it also stops Netscaler from working. Even thou Citrix released a new build today 123.81 it does not working with the latest version.
In order to fix the issue we need to add the netscaler URL to a JAVA exception, open the control panel applet.
And choose Edit Site list and add an exception.
After that, restart the browser and start again