Canon 6D Mark 2. Suddenly the camera can't format any of my cards. It says "Card cannot be accessed. Change card or format card with camera." I've done all that. There is data on my cards tht can be read on my computer. I've tried formatting in camera to no avail. Yikes! I don't need this right now. Any help?

Windows 10 Home Pro, 24gigs RAM, Gigayte mobo, i5 cpu.