Thanks for your reply. My version is 2.9. I can't open the file to look for any unusal symbols. The Protxt error message will not allow me to open the file. Fortunately, I printed the pages as I went along and I do not see anything unusual on the printed version on Page 41. I only got to page 69 on my first attempt to compile the book. I got to page 46 on my second attempt.
Is there a way to clean the file? Is there a way to keep this from happening?
My data base is quit extensive. Do you know of a program that I can switch to and be able to import the data base to it? I have years and years of work in this project. The thought of starting over again is quit depressing.