could be a corrupt font in your system. Does Word work ok?
try opening your character map & scroll through your fonts to see if they display ok
Have you installed any new programs recently?
Can you go back to an ealier restore point & try FM again?
To check operation of fonts with FileMaker
Create a folder on your desktop & move all your fonts to it but leave the arial font in there so you only have the one font.
Restart your system & try filemaker again, if you still have the same problem move the arial font to the desktop folder & include one of the other fonts instead, again restart your system & try again.
If you find all works ok then you can assume that at least one font is corrupted(arial), try dropping in a selection of fonts say20-3 or so & restart your system if all is still ok drop more in there& repeat the process unitl a fail.
Remember which fonts you transferred each time so you can remove & isolate as batchs if youget a fail.
If it is a font issue I would normally suspect a truetype font first
Hope this Helps