Hey

I've seen others on this forum with problem with the K2 comments system.
Public comments seems to work, but change it to registered user only and it do not. Simply no message box appears.
I tried with different templates including any one of them coming with Joomla, but same result.
I decided then to make a whole new installation with Joomla on a new database, but to no avail. Same result
Btw i'm using the latest version of Joomla 3.5.1

Best regards
Martin Nørresø Haase
Denmark

Are there any js errors in your browser developer tools console?

It does not work!!!

If the public's comments will be shown on the form if registration is connected, it can not be seen. !!!!

I made a virgin installation. Joomla 3.6 and K2 is a virgin.

xxx.mag.eastweb.hu/index.php/k2/item/1-items
Login: user, user

This solution is something ??

My client wants to achieve only be registered members of the comment functionality and only they are able to comment on your articles.

The comments in the link you provided are working as expected.