Or... take a step back....
When a ControlLogix controller encounters a corrupted user program in RAM, it intentionally erases the program in RAM. This is normal behavior but it is often referred to as the controller "losing" the program.
When a ControlLogix encounters a corrupted or invalid controller memory image on the CompactFlash or Secure Digital removable memory device, it cannot load and run that program, so it sets the Type 7 Code 41 fault.
But (to my knowledge) it doesn't attempt to erase or modify the file on the CF/SD card.
So if your examination of the CF card shows an empty directory, it's very likely that it was not there prior to the load-on-powerup event. Have you put the CF card into a card reader and read it with a computer, or are you looking only at the RSLogix 5000 Nonvolatile Memory window and seeing a "no image on card" message ?
Some of the issue may depend on how the image file was created. If it was written from a file archive by a computer, maybe it was corrupted in the process. If it was created by the 1756-L60 itself in a "Store to NV" process, then the card failed to properly create the file, suggesting a hardware, format, or file system problem.
It's really good that you're testing this functionality. Failure to test Restore after Backup, in all sorts of computer system contexts, is a classic blunder.