The first thing you want to do in this process is to make absolutely sure that you have the right upgrade file for your camera by using the firmware finder HERE. if you are performing a firmware upgrade for multiple cameras MAKE SURE YOU CHECK THE SERIAL NUMBER FOR EVER CAMERA YOU ARE UPGRADING!
once this is open look for the value "verify" as seen in the picture below and change this value from "true" to "false".
save and close this document. from this point, you should be good to continue with the upgrade process.
please reach out to support if you are still having issues with upgrading the firmware on your camera.