Do you actually write your story directly on the submission page? Oo
If so, don't! Write them in a text editor. It will auto correct you a bit, you will have a better grasp of how your story look, and above all you won't risk losing your work! For the ARchive is an old website so accidentaly going back one page and returning to the story submission won't have all your writting saved up like in modern sites.
Submitting a story should be a one minute process of copy pasting your _title_, summary, and chapters.