Thanx! I have tried that. No error messages the button is just dead
Then provide me via Messenger your server Control Panel and UNA studio accesses.
I got this message when trying: YOUR CURRENT MEMBERSHIP (STANDARD) DOESN'T ALLOW YOU TO 'NEW CONVERSATION'.
UPDATE: We've checked together this trouble. So the reason was like in my previous message, too strict security. After the request to support it has been fixed.