Applet Permission Denied

All I have signed all the jar files including appletviewer.jar also . i am running latest version of JDK . I was running and viewing applet successfully till today afternoon , but suddenly i am getting this exception now . i can not understand what is happening ... please, help me asap.

exception: Permission denied: null.
java.lang.SecurityException: Permission denied: null
    at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Exception: java.lang.SecurityException: Permission denied: null
Exception in thread "thread applet-applet.EmbeddedViewerApplet.class-3" java.lang.SecurityException: Permission denied: http://localhost:8080/ExtraCare/resources/appletviewer.jar
    at sun.plugin.util.GrayBoxPainter.setProgressFilter(Unknown Source)
    at sun.plugin2.applet.Plugin2Manager.setupGrayBoxPainter(Unknown Source)
    at sun.plugin2.applet.Plugin2Manager.showAppletException(Unknown Source)
    at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
    at ja开发者_如何转开发va.lang.Thread.run(Unknown Source)

Thank You Mihir Parekh +91 94266 21000 .

Are you using FireFox? Any chance you recently updated to version 3.6.14?

Check this out...

https://support.mozilla.com/en-US/kb/pogo-and-other-java-pages-dont-work

You might want to wrap your calls in a doPrivileged block. Beforehand, you might want to call checkPermission on the method you want to invoke. Here are two useful articles. http://download.oracle.com/javase/1.4.2/docs/api/java/security/AccessController.html

http://www.raditha.com/java/sandbox/unsigned.php

However, if you use jnlp deployment, System.setSecurityManager(null) should solve your problems and you will have more privileges of your applet, allowing you to effectively escape the browser sandbox without much hassle. Keep in mind though, that doing so is not only not a good practice, but actually does expose the user of your applet to malicious code.