the md5 checksum wws actually correct.
maybe the disk image problem is because i worn out the sdcard a bit by hosting the system on it 7x24 for over 2 years.
i seen similar warning before, but the image actually works after i burn it with win32disk imager to sd๐
you may pick a cheap 16gb tf card to test it if you are in doubt, i used v0.2 image (non xz one๐ ) the restore my nas after i screwed the system before.