Like many of you guys out there, I too was extremely disappointed in learning that the recent save editor released by Cyber Gadget was patched in the latest PS4 Firmware 4.50.
I did some examining of what exactly happens when you copy a save from a 4.50 system. Basically two errors occur. If you the save you are using is on a lower FW than 4.50 (backup from a USB, or off the Internet) the system won't allow you to copy it onto itself or use it unless the original from the console itself it up-to-date and then copied over. And if you copy a save from 4.50 onto a USB drive it appears as corrupted on a firmware below it.