Exception: java.lang.ClassNotFoundException: com.fintrack.FtCFDTraderApplet.class

Question

I am using Mozilla Firefox version 3.6.18. I don't want to update because last time I updated (recently) the newer version was such an unfriendly dog that after a few days I went back to the version I am still using. It works well! BUT, after I have successfully logged into my Macquarie Prime account, I then click the link to the trading platform and get a Java error message.
Okay, perhaps Macquarie could have done a better job of making their java code cross-platform compatible, but I installed the latest version of Java and then tried again. With the newer version of Java, the error message changed, but I still got the following:
"Java Plug-in 1.6.0_26
Using JRE version 1.6.0_26-b03 Java HotSpot(TM) Client VM
User home directory = C:\Documents and Settings\adrian
c: clear console window
f: finalize objects on finalization queue
g: garbage collect
h: display this help message
l: dump classloader list
m: print memory usage
o: trigger logging
q: hide console
r: reload policy configuration
s: dump system and deployment properties
t: dump thread list
v: dump thread stack
x: clear classloader cache
0-5: set trace level to <n>
load: class com.fintrack.FtCFDTraderApplet.class not found.
java.lang.ClassNotFoundException: com.fintrack.FtCFDTraderApplet.class
at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source)
at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Exception: java.lang.ClassNotFoundException: com.fintrack.FtCFDTraderApplet.class"

Answer 1

Hmmm...
I forgot to state what I actually WANT!
Is there any way (anywhere) I can get the missing class/applet and manually instal it? If so, would that fix the problem?
Thanks to anyone who can help me (without getting me lost in a never-ending swamp of excessively geeky technicalities; I don't need a "perfect" system - just access to my trading platform.)?
`