To reproduce, run the attached program on a Linux machine with a security manager enabled (or run it as an untrusted applet or Web Start app).

$ java -Djava.security.manager -webviewapp.Main

Exception in Application start method
Workaround until RT-13281 is implemented: keep toolkit alive
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(Unknown Source)
at com.sun.javafx.application.LauncherImpl.launchApplication(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.launcher.LauncherHelper$FXHelper.main(Unknown Source)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(Unknown Source)
at com.sun.javafx.application.LauncherImpl.access$000(Unknown Source)
at com.sun.javafx.application.LauncherImpl$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.security.AccessControlException: access denied ("java.util.PropertyPermission" "user.home" "read")
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPropertyAccess(Unknown Source)
at java.lang.System.getProperty(Unknown Source)
at com.sun.glass.ui.Application.getDataDirectory(Unknown Source)
at javafx.scene.web.WebEngine.defaultUserDataDirectory(Unknown Source)
at javafx.scene.web.WebEngine.applyUserDataDirectory(Unknown Source)
at javafx.scene.web.WebEngine.load(Unknown Source)
at webviewapp.Main.start(Main.java:32)
at com.sun.javafx.application.LauncherImpl$8.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl$7.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl$6$1.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl$6$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$6.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
at com.sun.glass.ui.gtk.GtkApplication.access$200(Unknown Source)
at com.sun.glass.ui.gtk.GtkApplication$6$1.run(Unknown Source)
... 1 more
Exception running application webviewapp.Main