FAQ
From Synfig Studio :: Documentation
- Missing icons? synfig/studio doesn't render anything? You probably compiled synfig with g++ 4.1 using optimisation level 2 or higher. g++ has a bug that prevents synfig from compositing the images properly. Please recompile synfig using ./configure --enable-optimisation=0 or disable optimisation and then rebuild the the synfigstudio images. The binary packages for some GNU/Linux distributions are affected by this. Bug #1509627