it seems there is a problem with an image.
I use the doc
https://docs.poppy-project.org/en/
Download the image of the operating system
and
Write the operating system image to the SD card
with the file
2017-04-06-poppy-ergo-jr.img.zip
i haven’t got any problem
But with the second one
poppy-torso-xu4-2016-05-25.img.zip
I have got always the same error when i use Etcher