I recommend you update the Adobe Flash to the latest version in order to enjoy your creations inside the browser. Also, beginning with version 52 Firefox disabled any NPAPI plugins, except Flash. If Photodex had a plugin installed in Firefox, it won't work anymore unless you download an older version of Firefox and disable the updates, but then again you will be vulnerable to web infections.
It's a strange situation, but Photodex should release a compatible plugin and until then, simply uninstall latest version and choose a previous one from the following link: https://ftp.mozilla.org/pub/firefox/releases/
