Caused by: java.lang.NullPointerException
at sun.awt.X11FontManager.getDefaultPlatformFont(X11FontManager.java:779)
at sun.font.SunFontManager$2.run(SunFontManager.java:433)
at java.security.AccessController.doPrivileged(Native Method)
at sun.font.SunFontManager.<init>(SunFontManager.java:376)
at sun.awt.X11FontManager.<init>(X11FontManager.java:32)
Solution
sudo apt-get install fonts-dejavu-core
sudo apt-get -y --no-install-recommends install libfontconfig1