I had this problem too.
I have a valid Samsung Gear360 and I could not get the Samsung Gear360 Serial Number to be read as valid by the Mac software used to edit the 360 video into Equirectangular. So I had old 360 footage that needed to be turned from fish-eye into equirectangular.
This meant I could not load the 360 footage into any editing program like Final Cut or Youtube without first sending it through "Dual-fisheye Viewer" for Mac. Serious pain.
I even found that some 360 mp4 files from the original Gear360 were MISSING SOUND entirely. I solved this by importing these videos into Handbrake, then exporting them new again. You can grab the audio there if you want, but the videos sometimes lost their 360 codec.
HERE IS THE WORK AROUND!
1.) I had my old 360 source footage from when I downloaded the mp4 files directly from my Gear360 memory card.
2.) I put those mp4 source files back onto the memory card, in the correct directory, and loaded it INTO THE CAMERA AGAIN. So it could be read by the Gear360 app on my Samsung phone. You connect your phone to the camera, and you should be able to see the original mp4 footage on your phone.
3.) I then reimported the mp4s from the Gear360 camera into my phone Gallery on my Samsung phone. The phone app automatically processed the 360 footage from dual fisheye into equirectangular.
4.) Android File Transfer got the mp4s onto my Mac.
5.) Then you can upload the mp4 to Youtube or Final Cut Pro.
SOLVED!
So frustrating that Samsung stopped supporting their own software, but this *is* the only work around I found.
Otherwise you have to go through tons of old files from 2017 which is just a pain.
