( That's assuming that the swf file you already downloaded for some astronomical reason hasn't already screwed up your computer by going to a sketchy site in the first place. If you aren't careful with what swf files you're running on fierfox you could screw up the browser's programing. Here is the link that will show you on how to run local swf files from your computer to firefox: ĭisclaimer!: What this dose is it allows you to run swf files from you computer on the browser. I know I am tardy to the party when it comes to this, but here is the solution for the firefox not running swf files, happy gaming you degenerates!