SlidePress

I installed SlidePress, SlideShowPro standalone and SlideShowPro Director. I use the Atahualpa theme.
SlideShowPro Director works fine,
When creating a gallery in the SlidePress menu, it seems that the system has all the required information but the ‘preview’ button in ‘Overview’ sometimes works, sometimes does not work.
However, if I add the link to the gallery from the Page editor, the gallery does not show on the screen. Instead of the gallery I only have the message about FlashPlayer and JavaScript.

URL is https://www.embernard.fr

Thanks in advance for any advise.
Etienne