K1 CFS upgrade kit corrupted usb drive

Went to update the firmware on k1 for CFS upgrade using USB drive that came with the upgrade kit and it says that the iso image for the upgrade is corrupt.
CR4CU220812s11_ota_img_V2.3.5.33

The version of firmware on my K1C is 2.3.5.27 and when I check it says that is the latest version.