Crash opening html page with Impress

Using LO 4.2.1.1 in Kubuntu 13.10. Opening my web page (“index.html”) by selecting it in the file manager (Dolphin) and choosing “Open With” LibreOffice Impress worked fine yesterday afternoon, and I was able to do a little editing. But last night and today it’s crashing/freezing. On restart LO claims “successful recovery” but freezes when I click “Finish.”

Any suggestions? It’s a pretty simple page, with several photographs and some hyperlinks to other pages.