Probably you lack the ttf fonts (required for P3D, was OPENGL). The sketch works fine for me on my linux box (ArchLinux). Include the ttf fonts in your data directory and you should be good to go.
PS: if you start to do anything serious in P3D sketch you may need to disable and enable depth test (and or restore camera to see fonts).
- hint(DISABLE_DEPTH_TEST);
- .....text
- hint(ENABLE_DEPTH_TEST);