Have 64GB Lexar SD card that reads all files fine in both of my 5D Mk4s but will only copy half of card before error message- unable to copy file unreadable. Card had been tested, copied, tested, copied and formatted fine before this message. Help
All: Thanks for all the answers- problem has been solved. Turns out that the new SD card and an old card reader were not happy with each other. When I put the card a new reader all files came up- no losses. Phew. Curious that older USB reader sho...
