The Java class file "xxx.class" could not be launched.

[piratemacfan]

I'm just a statistics teacher, trying to open an applet that came on the CD-ROM accompanying the text book.

For the last two years, when I clicked on a file [one of several others that also used to work] called PopSampleApplet.class a little applet would open where [in this case] I could play around with different sample sizes blah blah blah.

***Today, when I tried to open PopSampleApplet.class, I got this message:

The Java class file "PopSampleApplet.class" could not be launched.​

What is my next step?

---------
iMac summer 2007
running
Mac OS 10.8.4.

Elementary Statistics 11th ed with Technology Update, by Mario F. Triola
(2012).

 

[kfordham281]

If the file previously opened in Safari, it could be related to this recent Java security issue that Apple blocked: http://9to5mac.com/2013/08/29/apple...in-blocker-to-disable-new-java-vulnerability/