The FontFormatException sounds interesting. This is thrown if the PFR file is corrupt in some way. The good news is that the STB has at least parsed the font index file, which is more then was happening when you got the FontNotAvailableException.
Can you please send me some pfr files or tell me the location where I can get. I've only pfr of Tiresias font. And if possible send the pfr of different languages.
Is there any converter available to convert ttf to pfr.