So, lately I've had this problem where every now and then I would go to open the ATC text window (or it would pop up on it's own after ATC tells me something) and the box would be there but no text would be there. This applies to all text, for instance if I set the parking break I just get the red background at the bottom part of the screen where it should say "Press . to release parking break" and also the cokpit "tips" just show a little white rectangle the size the text should be
FS2004 doesn't start like this, it happens sometime during the flight and won't fix itself until I exit and restart FS.
The "responses" work but if I need to request a different runway or something like that it's really hard to try and memorize all of those number responses