After you have created the template you want in FusionPro, you create for output a number of files including the file "assets.dat." Now it is very important that you rename this file as it contains, among other things, the font information for that template. If you don't rename the file to a unique name, then when you upload assets.dat you will overwrite a previous copy of that file. All of your template files are kept in one subdirectory. So, if you don't rename the file, then a previous template using special fonts might not have the font information it needs to render the text the way you want it to.
I rename the assets.dat file the same name as the pdf file. That way you know it is unique and you can keep track of it.