Hi all,

If you are using JDK8, and running the offending program using strace causes entries like this one:

     java.lang.ClassCastException: sun.awt.image.BufImgSurfaceData cannot be cast to sun.java2d.xr.XRSurfaceData

Then it's not an X2Go bug, it's a Java bug. See http://bugs.java.com/bugdatabase/view_bug.do?bug_id=7172749

Many Java programs are affected when run over X2Go.
The only workaround I've found is downgrading to JDK7, where the bug is not present.
Presumably Oracle will solve it in JDK9, but I don't have the time to extensively test it.
Hope that helps!
Kind regards,