Thank you for your post.
First, clear the cache. Since you are on a Macintosh, go to the folder:
Hard Disk -> Applications -> Utilities -> Java -> Java Preferences -> Network Tab -> Delete Files button
You may have also updated the latest Java update from Apple. If so, find the "admin_console_webstart.jnlp" file that was downloaded (possibly in the user Downloads folder), control-click the file, and set it to open with: /System/Library/CoreServices/Java Web Start
You should then be able to launch.