How can I edit the Flash SWF files?

Answer 1

You can import SWF files into Adobe Animate (formerly Flash) and break them apart to utilize the visuals as they look, but the layers and assets that were used to create the SWF file are not retained within the SWF file itself. Think of it as a final rendered movie. All of the visual effects, smoke, fog, explosions, that created the final image are layered together in a compositing software like After Effects or Nuke. But you can't take the final rendered video and pull all those assets apart to change the video. You have to have the original file and all of the rendered assets that created it. In this case, it's the .fla file that's missing. I hope that answers your question.