I've last version (2.0)
I integrated the chat plugin by copying the downloaded files to plugins, then from ACP I installed the plugin without any errors.
I tried http::/MIO_SITO/plugin/chat/index.php and the chat is open and it's beautiful.
but, if I go to write and I click SEND does not appear in any written chat, and also in the list of users do not see my username.
The same thing happens if there are more users: no one sees anything and the list is empty username.