I am currently having this issue. My camera is a few years old (EOS Rebel T6) but only recently started giving me this error in June. I've been using the same SD card for months, the first time it happened reinserting didn't fox it and I couldn't format it. I messed around with it for a bit but couldn't figure it out so I left it alone. Picked it again after a few days and it worked just fine. Now it's doing it again.
