Applets now are required to contain additional information in their .jnlp files to document the files used, either external or local. But if you are working with older code, such as the FileMaker 11 Server Admin Console, the required manifest information is missing and your applet will halt with an exception like this:
java.lang.SecurityException: Missing required Permissions manifest attribute in main jar: http://localhost:16000/admin-client-lib/admin-console-client.jar at com.sun.deploy.security.DeployManifestChecker.verifyMainJar(Unknown Source) at com.sun.deploy.security.DeployManifestChecker.verifyMainJar(Unknown Source) at com.sun.javaws.Launcher.doLaunchApp(Unknown Source) at com.sun.javaws.Launcher.run(Unknown Source) at java.lang.Thread.run(Thread.java:744)
Adding in the missing manifest is obviously preferable, but when not in a position to do this we can workaround this requirement with the new Exception Site List dialog in the Java control panel. You can get to this by clicking the Security tab and then the Edit Site List…
When entering the location, be sure to enter the exact path, including http or https and any port number. The hostname or IP address also must match exactly the one used in the .jnlp file.
New security requirements for RIAs in 7u51
Code signing: Understanding who and when