Updating to X8H_PLUS_LOLLIPOP_RC2 failed

Hello,

I am trying to update my box to the latest beta firmware:
minixforum/threads/x8-h-plus-lollipop-rc2-firmware-july-2017.16633/

I am using this method:
minixforum/threads/how-to-use-the-usb-zip-update-method-x6-x8-series-u1-u9-h.6828/

I've put the img file into a zip file and uploaded to a USB stick.

The device displays the following:

Start copy /udisk/X8H_PLUS_LOLLIPOP_RC2.ZIP to /tmp/sideload
Finding update package...
Opening update package...
Verifying update package...
E:...

Updating to X8H_PLUS_LOLLIPOP_RC2 failed