The issue described here is seen on Mac, I've no idea if it is OS specific or not.

If I bypass the launcher by taking "java -jar SceneBuilderApp.jar" then SB starts up correctly.
When using the launcher produced by the packager I get the stack below, which probably means FX classes haven't been found.

This behavior is a regression. With 8 u40 b10 we were facing the RT-38887, but after fixing the Info.list manually the launcher was doing well.

yjoan$ ./JavaFX\ Scene\ Builder\ 2.0.1
Picked up _JAVA_OPTIONS: -Dcom.oracle.usagetracker.config.file=/Users/yjoan/.usagetracker.properties
Exception in Application start method
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:363)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:303)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:875)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$147(LauncherImpl.java:157)
at com.sun.javafx.application.LauncherImpl$$Lambda$49/1681433494.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NoClassDefFoundError: javafx/scene/control/ButtonBar
at com.oracle.javafx.scenebuilder.kit.library.BuiltinLibrary.<init>(BuiltinLibrary.java:126)
at com.oracle.javafx.scenebuilder.kit.library.BuiltinLibrary.getLibrary(BuiltinLibrary.java:84)
at com.oracle.javafx.scenebuilder.kit.editor.EditorController.<init>(EditorController.java:256)
at com.oracle.javafx.scenebuilder.app.DocumentWindowController.<init>(DocumentWindowController.java:169)
at com.oracle.javafx.scenebuilder.app.SceneBuilderApp.makeNewWindow(SceneBuilderApp.java:467)
at com.oracle.javafx.scenebuilder.app.SceneBuilderApp.handleLaunch(SceneBuilderApp.java:388)
at com.oracle.javafx.scenebuilder.app.AppPlatform.requestStartMac(AppPlatform.java:207)
at com.oracle.javafx.scenebuilder.app.AppPlatform.requestStart(AppPlatform.java:99)
at com.oracle.javafx.scenebuilder.app.SceneBuilderApp.start(SceneBuilderApp.java:349)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$153(LauncherImpl.java:821)
at com.sun.javafx.application.LauncherImpl$$Lambda$55/799640930.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$166(PlatformImpl.java:323)
at com.sun.javafx.application.PlatformImpl$$Lambda$46/2052001577.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$null$164(PlatformImpl.java:292)
at com.sun.javafx.application.PlatformImpl$$Lambda$48/1274001472.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$165(PlatformImpl.java:291)
at com.sun.javafx.application.PlatformImpl$$Lambda$47/544724190.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
Exception running application com.oracle.javafx.scenebuilder.app.SceneBuilderApp