All webstart apps on Mac stuck with splash screen visible and following stack:

"main" prio=5 tid=0x00007fd091800800 nid=0x1c03 runnable [0x000000011022a000]
   java.lang.Thread.State: RUNNABLE
    at com.sun.glass.ui.mac.MacApplication._runLoop(Native Method)
    at com.sun.glass.ui.mac.MacApplication.runLoop(MacApplication.java:56)
    at com.sun.glass.ui.Application.run(Application.java:124)
    at com.sun.glass.ui.Application.Run(Application.java:119)
    at com.sun.javafx.tk.quantum.QuantumToolkit.startup(QuantumToolkit.java:271)
    at com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:122)
    at com.sun.deploy.uitoolkit.impl.fx.FXPluginToolkit.doInitIfNeeded(FXPluginToolkit.java:105)
    - locked <0x00000007e43dcc68> (a java.lang.Object)
    at com.sun.deploy.uitoolkit.impl.fx.FXPluginToolkit.warmup(FXPluginToolkit.java:168)
    at com.sun.javaws.Main.main(Unknown Source)

Similar problem can be reproduced with simple command line
       java -splash:~/picture.png -jar fish.jar

I.e. there is a conflict between AWT splash implementation and JavaFX.
AWT Splash implementation is used by webstart on Mac (and mac only) but we only show splash in the first JVM instance.
We do not use splash after relaunch.

Due to other recent improvements JavaFX apps do not need to relaunch on Mac and now we face this lock.

For 7u6 we should probably disable splash in webstart if we are running FX app.