Look at the attached NB project.
When the FXML file is opened with Scene Builder 1.1 (based on Fx 2.2), one get an FxmlParseException (see below).
1) This does not really provide useful information to the user. Having a dedicated exception for URL resolution problem would be much better.
2) It does not provide enough information to SB so that the tool can handle this correctly (by for instance opening the classpath setting panel, as we do with unknow classes for custom types)


The exception raised:

com.oracle.javafx.authoring.persist.FXMLDocument$FxmlParseException: Failed to load FXML file
at com.oracle.javafx.authoring.persist.FXMLDocument.makeParseException(FXMLDocument.java:400)
at com.oracle.javafx.authoring.persist.FXMLDocument.load(FXMLDocument.java:311)
at com.oracle.javafx.authoring.persist.FXMLDocument.checkLayout(FXMLDocument.java:239)
at com.oracle.javafx.authoring.persist.FXMLDocument.checkLayout(FXMLDocument.java:224)
at com.oracle.javafx.authoring.Project.forFxml(Project.java:835)
at com.oracle.javafx.authoring.Project.forFxml(Project.java:807)
at com.oracle.javafx.authoring.DesignerTool.loadFXMLLayout(DesignerTool.java:197)
at com.oracle.javafx.authoring.DesignerTool.loadFXMLLayout(DesignerTool.java:185)
at com.oracle.javafx.authoring.DesignerTool.commonInit(DesignerTool.java:513)
at com.oracle.javafx.authoring.DesignerTool.initFromRemote(DesignerTool.java:436)
at com.oracle.javafx.authoring.mbeans.SceneBuilderMgt$1.run(SceneBuilderMgt.java:31)
at com.sun.javafx.application.PlatformImpl$4$1.run(PlatformImpl.java:179)
at com.sun.javafx.application.PlatformImpl$4$1.run(PlatformImpl.java:176)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$4.run(PlatformImpl.java:176)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:76)
at com.sun.glass.ui.win.WinApplication._enterNestedEventLoopImpl(Native Method)
at com.sun.glass.ui.win.WinApplication._enterNestedEventLoop(WinApplication.java:96)
at com.sun.glass.ui.Application.enterNestedEventLoop(Application.java:384)
at com.sun.glass.ui.EventLoop.enter(EventLoop.java:83)
at com.sun.javafx.tk.quantum.QuantumToolkit.enterNestedEventLoop(QuantumToolkit.java:521)
at javafx.stage.Stage.showAndWait(Stage.java:397)
at com.oracle.javafx.authoring.util.dialog.AbstractModalDialog.showAndWait(AbstractModalDialog.java:84)
at com.oracle.javafx.authoring.util.dialog.ErrorDialog.showDetailsDialog(ErrorDialog.java:72)
at com.oracle.javafx.authoring.util.dialog.ErrorDialog.access$000(ErrorDialog.java:15)
at com.oracle.javafx.authoring.util.dialog.ErrorDialog$1.run(ErrorDialog.java:30)
at com.oracle.javafx.authoring.util.dialog.AlertDialog.actionButtonPressed(AlertDialog.java:72)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:75)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:279)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1444)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:69)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:217)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:28)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.Node.fireEvent(Node.java:6867)
at javafx.scene.control.Button.fire(Button.java:179)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:193)
at com.sun.javafx.scene.control.skin.SkinBase$4.handle(SkinBase.java:336)
at com.sun.javafx.scene.control.skin.SkinBase$4.handle(SkinBase.java:329)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:64)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:217)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:33)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3311)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3151)
at javafx.scene.Scene$MouseHandler.access$1900(Scene.java:3106)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1563)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2248)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:250)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:173)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:292)
at com.sun.glass.ui.View.handleMouseEvent(View.java:530)
at com.sun.glass.ui.View.notifyMouse(View.java:924)
at com.sun.glass.ui.win.WinApplication._enterNestedEventLoopImpl(Native Method)
at com.sun.glass.ui.win.WinApplication._enterNestedEventLoop(WinApplication.java:96)
at com.sun.glass.ui.Application.enterNestedEventLoop(Application.java:384)
at com.sun.glass.ui.EventLoop.enter(EventLoop.java:83)
at com.sun.javafx.tk.quantum.QuantumToolkit.enterNestedEventLoop(QuantumToolkit.java:521)
at javafx.stage.Stage.showAndWait(Stage.java:397)
at com.oracle.javafx.authoring.util.dialog.AbstractModalDialog.showAndWait(AbstractModalDialog.java:84)
at com.oracle.javafx.authoring.DesignerTool.showAndWaitDialog(DesignerTool.java:243)
at com.oracle.javafx.authoring.DesignerTool.showLoadError(DesignerTool.java:267)
at com.oracle.javafx.authoring.DesignerTool.loadFXMLLayout(DesignerTool.java:232)
at com.oracle.javafx.authoring.DesignerTool.loadFXMLLayout(DesignerTool.java:185)
at com.oracle.javafx.authoring.DesignerTool.commonInit(DesignerTool.java:513)
at com.oracle.javafx.authoring.DesignerTool.init(DesignerTool.java:457)
at com.oracle.javafx.authoring.SceneBuilderLauncher$RunningWithJMXInstance.launch(SceneBuilderLauncher.java:71)
at com.oracle.javafx.authoring.Main.start(Main.java:72)
at com.sun.javafx.application.LauncherImpl$5.run(LauncherImpl.java:319)
at com.sun.javafx.application.PlatformImpl$5.run(PlatformImpl.java:216)
at com.sun.javafx.application.PlatformImpl$4$1.run(PlatformImpl.java:179)
at com.sun.javafx.application.PlatformImpl$4$1.run(PlatformImpl.java:176)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$4.run(PlatformImpl.java:176)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:76)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:17)
at com.sun.glass.ui.win.WinApplication$3$1.run(WinApplication.java:67)
at java.lang.Thread.run(Thread.java:724)
Caused by: java.lang.IllegalStateException
at com.sun.javafx.fxml.builder.URLBuilder.build(URLBuilder.java:46)
at com.sun.javafx.fxml.builder.URLBuilder.build(URLBuilder.java:17)
at javafx.fxml.FXMLLoader$ValueElement.processEndElement(FXMLLoader.java:582)
at javafx.fxml.FXMLLoader.processEndElement(FXMLLoader.java:2464)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2169)
at com.oracle.javafx.authoring.persist.FXMLDocument$2.call(FXMLDocument.java:301)
at com.oracle.javafx.authoring.util.Utils.withFXMLDefaultClassLoader(Utils.java:2216)
at com.oracle.javafx.authoring.persist.FXMLDocument.load(FXMLDocument.java:298)
... 105 more