Unable to run BrowserSim

org.jboss.tools.vpe.browsersim.command.log:org.jboss.tools.vpe.browsersim

!ENTRY org.jboss.tools.vpe.browsersim 4 0 2014-02-13 18:05:42.700
!MESSAGE javafx/embed/swt/FXCanvas
Stack trace:
java.lang.NoClassDefFoundError: javafx/embed/swt/FXCanvas
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:791)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
        at org.jboss.tools.vpe.browsersim.ui.BrowserSim.setSelectedDevice(BrowserSim.java:444)
        at org.jboss.tools.vpe.browsersim.ui.BrowserSim.open(BrowserSim.java:150)
        at org.jboss.tools.vpe.browsersim.ui.BrowserSim.open(BrowserSim.java:125)
        at org.jboss.tools.vpe.browsersim.BrowserSimRunner.main(BrowserSimRunner.java:84)
Caused by: java.lang.ClassNotFoundException: javafx.embed.swt.FXCanvas
        at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
        ... 16 more