The direct cloning option that doesn’t use a backup file is not an option because it won’t work with the same URL given that the DNS can’t simultaneously point to the source and destination. So, I created the full backup, including database, sitemap, etc. It’s saved as a .zip which I’ve manually uploaded to the destination. However, the process immediately fails with the message “Cant read configuration file from the backup.”.
I tried it over with a .tar.gz and it had the same error. The archives are not corrupted.
I am not sure why you would mention sitemap since that is not an option in the UI. All you have to select is Full Backup, and optionally exclude some locations.
Can you tell us at exactly which step you see this message? And if possible, attach a screenshot of it.