This occasionally happens when something hiccups along the way. You can try backing all the way out and trying again, and if that fails, try clicking the horizontal rule button (last one in the button line) to force the text editor to insert a beginning character. If that also fails, you can try: a private browsing window, or clearing cache and cookies, or Logging out and back in and of course, capturing a Console Log ( Chrome , Firefox ) during the issue and filing a Help Center Request .