humm...could be that you have to have a CF card that is formatted for Raymarine. The one I was using was a cartography card that came with my system.
Unfortunately I don't have the Raytech software on my puter here at the house. I do recall that there were several options for exporting the waypoints from the software app on my computer to the CF card and that I had to try more than one of the options before the MFD would recognize the file. It seems that the option of exporting them directly to the CF card didn't work and that I had to select one of the options specific to the C/E Series and then navigate to the CF card in File Explorer as the location to save the exported waypoint file.
The only thing that ever works on an old boat is the owner.