I'm having issues with my Illustrator CS. Every time I try to save a file, it's giving me an error message "PDF File Format is having difficulties, error code 912504." I've looked it up everywhere I can think of and nobody can tell me anything. I can't make changes to the file and save them. I'm pretty sure it's not the permissions, because I went into the file and changed them all to read and write. Any ideas on what's going on here?