i/o error message

[maggiemae]

I am unable to even open the back up program. Get an I/O error but scandisk says there is no problem. HELP!! I have Windows 10.

[fireworker]

This message does not offer you "ignore error", why you can't run the program?
The "I/O error" can be caused by incorrect partitions geometry on the disk, or hardware problems. In both cases it is possible that chkdsk not be able to detect the fault, and for Windows, disk will look as completely serviceable.