The JavaFX GTK 2 library is deprecated and will be removed in a future release. The JavaFX runtime issues a warning if the GTK 2 library is requested on the command line via `java -Djdk.gtk.version=2`. The JavaFX runtime also issues a warning if the GTK 2 library is selected as a fallback, which happens if the GTK 3 library cannot be loaded. Application developers should avoid requesting the GTK 2 library.

See [JDK-8273089](https://bugs.openjdk.java.net/browse/JDK-8273089) for more information.