Apple has recently disabled automatic Java downloads for Mac OS X 10.7 users with a recent Java update. This change prevents Citrix Online products from downloading on your computer.
In order to restore this functionality, you must make a change to your Java preferences
In the top menu bar click the Spotlight
Enter Java preferences and click on the Java preferences search result
Click the General Tab
Check Enable applet plug-in and Web Start Applications
Close Java Preferences
Quit and re-open your browser and try your download again