Java was recently updated to the latest version, Java 7. This update introduced a new level of security that requires users to manage how and when web applets or applications run in your browser. This means that to access some web applications, you need to set up some exceptions in the Java Control Panel.
1. Click on the Start Menu and type "Java" into the search field. From there, click on "Configure Java".
2. Click on the "Security" tab and then click on the "Edit site List..." button.
3. On that page will be a box thay says "Click Add to add an item to this list." Click the add button below the box.
4. In the white box, enter the full URL of the website that you are trying to access, and then click "Add" again.
The exception has been added after this point. Go and check to make sure that the functionality of the website you are trying to use works.
Additionally, if you are still having problems, lower the security level (on the security tab) to "medium" instead of "high."
For additional information, be sure to check out the documentation provided by Java.
Configuring the Exception Site List
Why are Java applications blocked by your security settings with the latest Java?
How do I control when an untrusted applet or application runs in my web browser?