Is it possible to install version 16 from stock LaCie firmw?

[Cubytus]

My mistake. It seems to be working now, with ports 22, 80, 111, 139, 445. It doesn't see yet the 16 update.

[Jocko]

Now you need to upgrade to version 15.3 and then 16.0.

You must use the upgrade menu in the web interface to do it.

[Cubytus]

Got it. It doesn't auto-detect new available firmwares, but provides a web interface for a manually-downloaded file.

[Jocko]

Maybe you need more details.

By default, the auto detect new available firmware feature is not enabled (you need to activate it). So after a first install, you get no warning.
This feature does not install the new firmware but just display an alert.