Comment 5 for bug 590771

http://www.archlinux.org/packages/community/any/ttf-liberation/

It seems that your distribution puts truetype fonts in /usr/share/fonts/TTF/. Until fontconfig support is added Lightspark expects ttf-liberation to be in /usr/share/fonts/truetype/ttf-liberation/LiberationSerif-Regular.ttf

You may solve the issue by creating a symlink or adding a distribution specific patch to modify the hardcoded path of the font (swf.cpp:1179)