So what site is this loading from?

Firefox, Chrome, and Internet Explorer each use a different version of Flash. NPAPI for Firefox, PPAPI for Chrome, and ActiveX for IE versions of Flash.

Sounds like you don't have the NPAPI Plugin version of Flash which Firefox needs to display .swf files.

If you go here you can select the correct Plugin version manually. Select the Operating System, then select for Firefox - NPAPI/ https://get.adobe.com/flashplayer/otherversions/

Or when using Firefox go here: https://get.adobe.com/flashplayer/ but make sure you deselect the Optional offers.

A while back, Firefox also stopped running SWF files that did not originate from the web (http: or https: address). So that prevented playing locally saved SWF files whose addresses in the address bar start with file:/// when you open them.

This was for security reasons related to strange protocols, but if you want to turn off this protection, you could.

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful or accepting the risk.

(2) In the search box above the list, type or paste https_ and pause while the list is filtered

(3) Double-click the plugins.http_https_only preference to switch the value from true to false to let Firefox run SWF files on file:/// and other non-web addresses

Thank jscher2000. that's what I need.