When trying to run an application that uses Java, the following error messages may appear:

Java applications are blocked by your security settings

or

Missing Application-Name manifest attribute

or

Missing required Permissions manifest attribute in main jar

Java has further enhanced security to make the user system less vulnerable to external exploits. Starting with Java 7 Update 51, Java does not allow users to run applications that are not signed (unsigned), self-signed (not signed by trusted authority), or that are missing permission attributes.

Contact the developer or publisher of this application, and let them know about the application being blocked. As a workaround, you can use the Exception Site List feature to run the applications blocked by security settings. Adding the URL of the blocked application to the Exception Site list allows it to run with some warnings.

It is highly recommended not to run applications that do not comply with the new security guidelines implemented in Java 7 Update 51. However if you still want to run these apps, run them only if you understand the risks and implications. Please the reference link at the bottom of this solution to view all of the risks involved in running these applications.

As a workaround, you can use the Exception Site list feature to run the applications blocked by security settings. Adding the URL of the blocked application to the Exception Site list allows it to run with some warnings.

NOTE: The Exception Site List feature is introduced in the release of Java 7 Update 51.

1. Access the Control Panel in your version of Windows.
   
   
2. Set the Control Panel view to 'Large icons'.
   
   
   
   
3. Click Java.
   
   
   
   
4. Click Security, and click Edit Site List.
   
   
   
   
5. Click Add.
   
   
   
   
6. Type the URL where the applet is hosted at, for example "http://www.example.com" or "https://www.example.com". It is recommended to use "https://" when available, since FILE and HTTP protocols are considered a security risk. If the URL where the applet is hosted is different from the URL of the web page from which the applet is launched, then you will need to add both the URL for the applet as well as the URL for the web page. Click OK to save the URL that you typed in.
   
   
   
   
7. Click OK.
   
   
   
   
8. If a security warning dialog comes up when trying to run your application again, click Continue.

Outcome

You can now run the applications that were being blocked by the security settings in Java.