Fix: Security settings have blocked a self-signed Java application

Teodor Nechita
by Teodor Nechita
Software Managing Editor
Eager to help those in need, Teodor writes articles daily on subjects regarding Windows, Xbox, and all things tech-related. When not working, you may usually find him either at the gym or taking a... Read more
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java self-signed app error

Java applets have been around for some time now, and they are still part of our everyday lives. However, not everyone is getting along with them all that well.

for example, some users have been reporting getting and error message when trying to run a Java applet which states that:

security settings have blocked a self-signed application

This error doesn’t seem to be tied to a specific version of Windows, as it is present in all versions, ranging from Windows 7 to Windows 10.

Since this issue block the functionality or java-based apps entirely, we’ve decided to create a guide that will help you bypass it with ease.

How can I unblock self-signed applications?

As far as causes go, there are 3 main reasons why this error may appear:

  • The application is unsigned
    • It has no certificate or is missing Publisher Information and Name are blocked by default
  • The user is trying to run a self-signed application from an untrusted authority
    • Self-signed certificates are also blocked by default starting with Java 7 Update
  • Application’s jar file is missing a permission attribute
    • These are blocked because an attacker might exploit the user by running the application with a different privilege level

1. Make an Exception Site List

  1. Press Windows + R
  2. Type in control.exe
  3. Click on Programs
  4. Click on Java
    • This will open the Java Control panel
  5. Go to the Security tab
  6. Click on the Edit Site List
  7. Inside the Exception Site List, click on Add buttonjava security exception list
  8. Paste the URL of the Java applet that you have issues with
  9. Click OK
  10. Click Continue when prompted by a security warning
  11. Try to open the applet again

In essence, any URL that you insert within the exception list should now work without any issues, regardless of the certification it may have.

2. Set the applet’s security level to High

  1. Press Windows + R
  2. Type in control.exe
    • This will open the Control Panel
  3. Click on Programs
  4. Click on Java
    • This will open the Java Control panel
  5. Go to the Security tab
  6. Under Security level, toggle the High buttonjava security high
  7. Restart the browser that you want to run the applet it

By following any of these methods, any self-signed applets should now be able to run easily on your browser. However, keep in mind that this a workaround that should only be used when dealing with applets that you trust.

This is because you are basically disabling security features within your PC.

If you’re aware of another way to solve this problem, share it in the comments section below so that others can give it a try as well.


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