Problems with the ATO Business Portal (or other Java Applets) & Mountain Lion's latest Java Update - this may help

MountainLion-Java-Applet-Plugin.txt

After I applied the latest Apple Security Update around October 20th 2012 my Java Applets would no longer work;
in particular the ATO Business Portal which I need to submit quarterly data to the Australian Taxation Office.
When using Safari I always got a "Missing Plugin" error - even after I "Enabled Java" in the Security Preferences of Safari.

I confirmed that my Java version was up to date by running:

java -version

which gave me:

java version "1.6.0_37"
Java(TM) SE Runtime Environment (build 1.6.0_37-b06-434-11M3909)
Java HotSpot(TM) 64-Bit Server VM (build 20.12-b01-434, mixed mode)

I then manually relinked to Java Applet plugin which solved the issue by running the following commands:

cd /Library/Internet\ Plug-Ins
sudo rm JavaAppletPlugin.plugin
sudo ln -s /System/Library/Java/Support/Deploy.bundle/Contents/Resources/JavaPlugin2_NPAPI.plugin JavaAppletPlugin.plugin

After restarting Safari I was able to use the Business Portal again.

Thanks for this. Easy solution. Much appreciated!