I am a great supporter of ISPConfig, and I convince a lot of people to actually use it. But sometimes I do run into some issues myself. I don't know if this might be something on my end, or a bug, but since ISPConfig 3.1.15, pure-ftpd-mysql user passwords are (if created new, or changed) now prefixed with: $6$rounds=5000$967270 (string is longer, but prefixed with this) So, all existing passwords seem to work, but the ones reset, or newly created, do fail. Server is Debian 9, with PHP 7.0, and ISPConfig 3.1.15. The same server did run the 3.1.14 series perfectly, without issues with FTP users, and resetting their passwords. This is a showstopper.