On some OSX installs, we're seeing a bug where Java works in 32-bit mode only for certain websites. This will likely be fixed soon but in the meantime you can switch Firefox to 32-bit mode by control-clicking (or right-clicking) on the Firefox.app in your Applications folder and selecting Get Info. Then check the open in 32-bit mode box.

Maybe you installed Java Embedding Plugin : you must uninstall it !
Search for this two files on your Mac :

• JavaEmbeddingPlugin.bundle
• MRJPlugin.plugin

and just delete them. (You might find them in /Applications/Firefox/Contents/MacOS/plugins or /Library/Internet Plug-Ins ... or elsewhere)
It worked for me, but your mileage may vary !

In Java Preferences, set applets to run in their own process.

Thanks. Tried all of these, but none worked so far. Keep sending ideas.

Ok this works for me! But what is the problem?

In my example the "Live Timing" applet on www.f1.com is working in Safari (is already running in 64-bit mode) and when I start Firefox in 32-bit mode. But this applet is not working when I run Firefox in 64-bit mode.

Does Safari use an other Java Plugin?

I've had the same problem, getting a missing plugin message, and then "No suitable plugins found." I'm on an Intel Mac with 10.6.7. I can confirm the issue was solved by switching to 32 bit mode.

Has this been addressed further? It has completely shut down my ability to run Command Center 2.0 on the TD Ameritrade web site. I've tried all the fixes to no avail.

None of the proposed solutions works for me. The Java console shows this exception:

java.security.AccessControlException: access denied (java.lang.RuntimePermission loadLibrary./System/Library/Java/Support/Deploy.bundle/Contents/Resources/Java/libdeploy.jnilib) Exception in thread "AWT-EventQueue-2" java.lang.Error: Unable to locate native library at com.sun.deploy.config.MacOSXConfig.loadNativeLibrary(MacOSXConfig.java:49) at apple.awt.ProcessUI.<clinit>(ProcessUI.java:7) at sun.plugin2.main.client.PluginEmbeddedFrame.windowDeactivated(PluginEmbeddedFrame.java:131) at java.awt.AWTEventMulticaster.windowDeactivated(AWTEventMulticaster.java:382) at java.awt.Window.processWindowEvent(Window.java:1880) at javax.swing.JFrame.processWindowEvent(JFrame.java:274) at java.awt.Window.processEvent(Window.java:1823) at java.awt.Component.dispatchEventImpl(Component.java:4736) at java.awt.Container.dispatchEventImpl(Container.java:2143) at java.awt.Window.dispatchEventImpl(Window.java:2478) at java.awt.Component.dispatchEvent(Component.java:4566) at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1850) at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:910) at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:592) at java.awt.Component.dispatchEventImpl(Component.java:4608) at java.awt.Container.dispatchEventImpl(Container.java:2143) at java.awt.Window.dispatchEventImpl(Window.java:2478) at java.awt.Component.dispatchEvent(Component.java:4566) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:680) at java.awt.EventQueue.access$000(EventQueue.java:86) at java.awt.EventQueue$1.run(EventQueue.java:639) at java.awt.EventQueue$1.run(EventQueue.java:637) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98) at java.awt.EventQueue$2.run(EventQueue.java:653) at java.awt.EventQueue$2.run(EventQueue.java:651) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87) at java.awt.EventQueue.dispatchEvent(EventQueue.java:650) at java.awt.SentEvent.dispatch(SentEvent.java:55) at java.awt.DefaultKeyboardFocusManager$DefaultKeyboardFocusManagerSentEvent.dispatch(DefaultKeyboardFocusManager.java:183) at java.awt.DefaultKeyboardFocusManager.sendMessage(DefaultKeyboardFocusManager.java:210) at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:385) at java.awt.Component.dispatchEventImpl(Component.java:4608) at java.awt.Container.dispatchEventImpl(Container.java:2143) at java.awt.Window.dispatchEventImpl(Window.java:2478) at java.awt.Component.dispatchEvent(Component.java:4566) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:680) at java.awt.EventQueue.access$000(EventQueue.java:86) at java.awt.EventQueue$1.run(EventQueue.java:639) at java.awt.EventQueue$1.run(EventQueue.java:637) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98) at java.awt.EventQueue$2.run(EventQueue.java:653) at java.awt.EventQueue$2.run(EventQueue.java:651) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87) at java.awt.EventQueue.dispatchEvent(EventQueue.java:650) at java.awt.SentEvent.dispatch(SentEvent.java:55) at java.awt.DefaultKeyboardFocusManager$DefaultKeyboardFocusManagerSentEvent.dispatch(DefaultKeyboardFocusManager.java:183) at java.awt.DefaultKeyboardFocusManager.sendMessage(DefaultKeyboardFocusManager.java:210) at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:286) at java.awt.Component.dispatchEventImpl(Component.java:4608) at java.awt.Container.dispatchEventImpl(Container.java:2143) at java.awt.Window.dispatchEventImpl(Window.java:2478) at java.awt.Component.dispatchEvent(Component.java:4566) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:680) at java.awt.EventQueue.access$000(EventQueue.java:86) at java.awt.EventQueue$1.run(EventQueue.java:639) at java.awt.EventQueue$1.run(EventQueue.java:637) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98) at java.awt.EventQueue$2.run(EventQueue.java:653) at java.awt.EventQueue$2.run(EventQueue.java:651) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87) at java.awt.EventQueue.dispatchEvent(EventQueue.java:650) at java.awt.SequencedEvent.dispatch(SequencedEvent.java:101) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:678) at java.awt.EventQueue.access$000(EventQueue.java:86) at java.awt.EventQueue$1.run(EventQueue.java:639) at java.awt.EventQueue$1.run(EventQueue.java:637) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98) at java.awt.EventQueue$2.run(EventQueue.java:653) at java.awt.EventQueue$2.run(EventQueue.java:651) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87) at java.awt.EventQueue.dispatchEvent(EventQueue.java:650) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188) at java.awt.EventDispatchThread.run(EventDispatchThread.java:122) Caused by: java.security.AccessControlException: access denied (java.lang.RuntimePermission loadLibrary./System/Library/Java/Support/CoreDeploy.bundle/Contents/Resources/Java/libdeploy.jnilib) at java.security.AccessControlContext.checkPermission(AccessControlContext.java:374) at java.security.AccessController.checkPermission(AccessController.java:546) at java.lang.SecurityManager.checkPermission(SecurityManager.java:532) at java.lang.SecurityManager.checkLink(SecurityManager.java:818) at java.lang.Runtime.load0(Runtime.java:764) at java.lang.System.load(System.java:1020) at com.sun.deploy.config.MacOSXConfig.loadNativeLibrary(MacOSXConfig.java:33) ... 88 more

The workaround here <https://bugzilla.mozilla.org/show_bug.cgi?id=668639#c4> worked for me.