Staging not working

I thought I’d give the new staging function a try, but I’m having no luck.

I have confirmed that the FTP details are correct, but what happens is that, after a lengthy pause (about 5 minutes, during which there’s no feedback on screen) it fails with an error of “FTP upload failed. Please make sure that above credentials has rights to create / delete files and folders.”

Checking the folder on the server I see that a folder called “wptc_staging_controller” has been created and within that are four placeholders called “bridge.php”, “pclzip.php”, “wp-db-custom.php” and “wp-modified-functions.php”, although each of them shows a size of 0 bytes.