Nextcloudpi for OndroidHC2 - defective installation image!?

I want to install nextcloudpi on an OdroidHC2 and need to flash an SD card with the correct installation software.

Image file download:
(NextCloudPi_OdroidHC2_03-28-20.tar.bz2) 29-Mar-2020 18:23 454884k)

md5 Check successful …Check
Unpack .tar.bz2 file also …Check

Unfortunately Etcher stops with a field message when trying to flash the SD card:

“The writer process ended unexpectedly. Please try again…”

Obviously the image file is defective!
Can anyone confirm that?