NPE in PrismFontLoader.java: Loading primary font factory failed

[Maurice]

I'm building a Yocto Embedded Linux image for the ARM based Udoo Board 
Quad. At the moment the build is good enough that JavaFX seems to see 
the Vivante GPU, but my small test program fails with a 
NullPointerException:
     at com.sun.javafx.font.PrismFontLoader.font(PrismFontLoader.java:172)
     at javafx.scene.text.Font.font(Font.java:148)
     at javafx.scene.text.Font.font(Font.java:228)
     at com.cuhka.Sample.start(Sample.java:18)

I tried several steps from the OpenJFX Font Setup 
<https://wiki.openjdk.java.net/display/OpenJFX/Font+Setup> page, I 
checked the presence of the ${java.home}/lib/fonts folder and it does 
exist. Running the program with -Dprism.debugfonts=true shows some error:

Loading FontFactory com.sun.javafx.font.freetype.FTFactory
Subpixel: enabled
Loading font factory failed com.sun.javafx.font.freetype.FTFactory
Loading font factory failed com.sun.javafx.font.t2k.T2KFactory
*** Loading primary font factory failed. ***
*** Fallbacking to com.sun.javafx.font.t2k.T2KFactory ***

What should be added to the platform for this to be fixed?

Maurice.