On Linux when I combine WorldWind and JavaFX I get the following error and the application halts.

"GThread-ERROR: GThread system may only be initialized once"

Looking at the dump I see the crash is in glass_general.cpp line 216 where it calls "g_thread_init(NULL)" you should always check g_thread_supported() before calling g_thread_init to ensure it is not already initialized" I downloaded javaFX 8 added the check recompiled and tested and it works.

This only happens under Linux because on Windows I think either JavaFX or Worldwind (or both) use DirectX instead of g_thread so the issue does not happen.

Need to be patched in java7 and updated in java8.