If this is the Error you are seeing:

Click on the "Details" button to get more information.  In the summary, you will see:

ERROR SUMMARY:  "+ Your Web browser settings do not allow you to run signed applications." 

This error summary indicates that there are security settings in your web browser  that are preventing the application from being able to download. 

Some people have had success by adding to their "Trusted Sites"  in the Tools>>Internet Options>>Security settings window in Internet Explorer: