Java warning on portlet pages: "Block potentially unsafe components from being run?"
When you view a page that contains a Network Manager portlet, such as the Network Views, Network Hop View, or Network Health View, you may see a warning message about potentially unsafe components. This is due to changes in the Java implementation, and is not caused by an unsafe component in Network Manager.
Oracle states that "Signed Java Web Start applications and applets that contain signed and unsigned components could potentially be unsafe unless the mixed code was intended by the application vendor".
More information can be found at: http://docs.oracle.com/javase/6/docs/technotes/guides/jweb/mixed_code.html
Note that though this technote describes the introduction of mixed code settings from release 19, it is only in the latest releases that warning messages are displayed to user. An example of such a message, "Block potentially unsafe components from being run?", is displayed below.
Depending on the question asked in the warning message, select the option that allows the Network Manager applet to run. In the example above ("Block potentially unsafe components from being run?"), select "No" so the code is not blocked from running.