Hello
I have the same issue when I define a second user of the panel username : "webmaster" /
webmaster@mydomain.com. If I log in with this user (login :
webmaster@mydomain.com) and run the autoinstall script for wordpress : I got the error : "Error: Installation of WordPress at
http://thedomain.com/ failed. invalid values passed for settings of application resource; details for setting with id 'admin_name': Please make sure the text you entered starts with a letter and continues with either numbers, letters, underscores or hyphens."
I except the problem is the following : the script try to install wordpress with the administator login "webmaster@mydomain.com" and should instead use the login name "webmaster" (not the full email address).
When I install using the main "admin" login of plesk it works well but create the instance of wordpress with user "admin" that is subject of attack.
Will be great to have a fix for that quickly. (and a way to report a bug on your website !)
Regards