FULL PRODUCT VERSION :
java version "1.8.0_60"
Java(TM) SE Runtime Environment (build 1.8.0_60-b27)
Java HotSpot(TM) Server VM (build 25.60-b23, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Linux banshee 3.13.0-63-generic #103-Ubuntu SMP Fri Aug 14 21:43:30 UTC 2015 i686 i686 i686 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
When loading a web page in a new WebView, I frequently see this exception (note that none of my own code is in the call stack):

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at com.sun.javafx.webkit.theme.ScrollBarThemeImpl.getThumb(ScrollBarThemeImpl.java:409)
at com.sun.javafx.webkit.theme.ScrollBarThemeImpl.thumbPosition(ScrollBarThemeImpl.java:293)
at com.sun.javafx.webkit.theme.ScrollBarThemeImpl.getThumbPosition(ScrollBarThemeImpl.java:389)
at com.sun.webkit.network.URLLoader.twkDidFinishLoading(Native Method)
at com.sun.webkit.network.URLLoader.notifyDidFinishLoading(URLLoader.java:838)
at com.sun.webkit.network.URLLoader.lambda$didFinishLoading$96(URLLoader.java:829)
at com.sun.javafx.application.PlatformImpl.lambda$null$174(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$175(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
at com.sun.glass.ui.gtk.GtkApplication.lambda$null$50(GtkApplication.java:139)



STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
My code to load the webpage is:

        WebView browser = new WebView();
        browser.getEngine().load(url);
        Tab tab = new Tab();
        tab.setGraphic(getWebIcon());
        tab.setContent(browser);
        tab.textProperty().bind(browser.getEngine().titleProperty());
        tabPane.getTabs().add(tab);
        tabPane.getSelectionModel().select(tab);

Which I think is pretty standard. The problem occurs when viewing an HTML page with an anchor. The pages I am loading are Javadoc webpages -- links very similar to https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#contains-java.lang.CharSequence- but the links are file: links on my local machine to locally generated Javadoc

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I expect not to have an exception. It does not seem to prevent the page displaying at the right location, but obviously an exception isn't right.
ACTUAL -
The exception included above.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at com.sun.javafx.webkit.theme.ScrollBarThemeImpl.getThumb(ScrollBarThemeImpl.java:409)
at com.sun.javafx.webkit.theme.ScrollBarThemeImpl.thumbPosition(ScrollBarThemeImpl.java:293)
at com.sun.javafx.webkit.theme.ScrollBarThemeImpl.getThumbPosition(ScrollBarThemeImpl.java:389)
at com.sun.webkit.network.URLLoader.twkDidFinishLoading(Native Method)
at com.sun.webkit.network.URLLoader.notifyDidFinishLoading(URLLoader.java:838)
at com.sun.webkit.network.URLLoader.lambda$didFinishLoading$96(URLLoader.java:829)
at com.sun.javafx.application.PlatformImpl.lambda$null$174(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$175(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
at com.sun.glass.ui.gtk.GtkApplication.lambda$null$50(GtkApplication.java:139)
at java.lang.Thread.run(Thread.java:745)

REPRODUCIBILITY :
This bug can be reproduced often.