I've used UNiTE some years ago and am now attempting to set up the same automated cloning from a live site to a dev site to be able to experiment more securely, especially with upgrading to J4.
php unite.phar restore unite.xml
results in the following error message
In Api.php line 151: Invalid JSON data returned from the server: ‘Array’.
Full verbose output attached.
The remote server is obviously contacted and thinks the backup is on-going (at least for a while). A full debug log from the remote is also attached.