Cannot open Java applet pages with error "java.lang.SecurityException: attempted to open sandboxed jar Windchill/wt/security/security.jar as a Trusted-Library" in Windchill PDMLink

security: resource name "wt/security/WTTransferAction.class" in http://<xxx>/Windchill/wt/security/security.jar : java.lang.SecurityException: attempted to open sandboxed jar http://<xxx>/Windchill/wt/security/security.jar as a Trusted-Library
java.lang.SecurityException: attempted to open sandboxed jar http://<xxx>/Windchill/wt/security/security.jar as a Trusted-Library
    at com.sun.deploy.security.CPCallbackHandler$ParentElement.checkResource(Unknown Source)
    at com.sun.deploy.security.DeployURLClassPath$JarLoader.checkResource(Unknown Source)
    at com.sun.deploy.security.DeployURLClassPath$JarLoader.getResource(Unknown Source)
    at com.sun.deploy.security.DeployURLClassPath$JarLoader.getResource(Unknown Source)
    at com.sun.deploy.security.DeployURLClassPath.getResource(Unknown Source)
    at sun.plugin2.applet.Plugin2ClassLoader$2.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.plugin2.applet.Plugin2ClassLoader.findClassHelper(Unknown Source)
    at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
    at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
    at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
    at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
    at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
    at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at wt.clients.checker.LookAndFeelChecker.configureClient(LookAndFeelChecker.java:38)
    at wt.clients.checker.Checker.configureClient(Checker.java:154)
    at wt.clients.checker.CheckerApplet.init(CheckerApplet.java:67)
    at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)