As is stated in this article, the latest version of the jdk for ARM processors (JDK 8u33 for ARM) no longer supports JavaFX Embedded. As a result, b4j gui programs will not run on arm devices like raspberry pi.
I have tried gluon and openjfx as these two threads said:
UI applications are officially not supported on arm boards in the last three years. If you search the forum you might find references to other versions of Java that do include JavaFX. I'm not sure whether they work properly or not.