Hi Mary,

If you encounter a Java applet in your web browser, and see a window display that says Application Blocked by Security Settings, don’t fret. Your security settings have blocked an application from running with an insecure or expired JRE. It may be due to running an old version of Java on your computer.
This alert displays to help protect your computer system from potential vulnerabilities that may exist in older versions of the plug-in. By blocking the application, it is not allowed to run in your web browser.

Java 7u10 introduced the ability to manage when and how untrusted Java applications (i.e. an application that is digitally signed by an unknown publisher, or a certificate that has not been issued by a trusted Certificate Authority) will run if they are included on a web page.

Fix 1: If you are allowed to install/upgrade software on your computer, please install latest Java first, relaunch the web browser, and try again.

Fix 2: Setting the Security levels through the Java Control Panel

1. In the Java Control Panel, click on the Security tab.
2. Select the desired Security level.
3. Click Apply.
4. Click OK to save changes made to the Java Control Panel.

Java Control Panel - Java 8u20 and later versions
Java Control Panel - Java 7


Security levels in the Java Control Panel
Very High
This is the most restrictive security level setting. All the applications that are signed with a valid certificate and include the Permissions attribute in the manifest for the main JAR file are allowed to run with security prompts. All other applications are blocked.

High
This is the minimum recommended (and default) security level setting. Applications that are signed with a valid or expired certificate and include the Permissions attribute in the manifest for the main JAR file are allowed to run with security prompts. Applications are also allowed to run with security prompts when the revocation status of the certificate cannot be checked. All other applications are blocked.

Medium (removed from Java 8 Update 20 and later versions)
Only unsigned applications that request all permissions are blocked. All other applications are allowed to run with security prompts. Selecting the Medium security level is not recommended and will make your computer more vulnerable should you run a malicious application. 


If you decide that you still want to run a blocked application, run it only if you understand the risk and implication of doing so.

1. Click on the Windows "Start" menu in the lower-left corner of the screen --> "Control Panel" --> "Programs" --> "Java".
2. In the "Java Control Panel" window that appears --> Click the "Security" tab.
3. If there is a "Exception Site List" section in this window, click on the "Edit Site List..." button --> Click the "Add" button --> Type in the web server location for the Java applet like "http://www.math.ucsd.edu/" --> Click the "OK" button --> Click the "OK" button.
4. If there is no "Exception Site List" section in this window --> Slide the "Security Level" indicator from "High" down to "Medium" --> Click the "Apply" button --> Click the "OK" button.
5. Close ALL of the open windows. You must completely QUIT the web browser or this workaround will fail.
6. Re-launch the web browser.
7. Go to the Java applet.
8. When the "Security Warning" window asking "Do you want to run this application?" appears, if there is a "I accept the risk and want to run this app." option, checkmark it ON first then --> Click the "Run" button.
9. The Java applet should load OK now. You may need to click on it to start it.
10. When you are done using the Java applet, you should change the Java "Security Level" back to "High" if you had lowered it down to "Medium" earlier.

I hope this helps.

Regards,
Lokesh