RobM

This problem isn't specific to Fuji. I have a Sony a6500 with the same problem on a 64G and a 128G flash cards. The flash card appears on the desktop. I drag the flash-drive folder with photos to my desktop. Finder shows a progress bar for the copy, creates the target folder on the desktop, then after successfully copying zero or more photos, reports that a file is unreadable and stops. Trying to copy the error photo alone also fails. Sometimes I can copy other photos, sometimes not. And as OP notes, I have to force eject. Everything was working before Catalina. So something is gummed up in Catalina. My workaround is to plug the camera in via USB. Catalina mounts the flash drive on the desktop, and copying works fine. BTW, I was able to run Disk Utility on the card, and it finds no problems. Rob