Chat keeps loading and loading and not opening.
and error displayed in console is:

rcn-net:332 Uncaught TypeError: window.addEvent is not a function
    at rcn-net:332
(anonymous) @ rcn-net:332
jquery-migrate.min.js:2 JQMIGRATE: Migrate is installed, version 1.4.1
chat:328 Uncaught TypeError: window.addEvent is not a function
    at chat:328

Zdravo Goran.

Thank you for contacting us.
I disabled Easy jQuery and issue is still present.
Could you confirm that? If yes, that it means that chat script clashes with something else...

Zdravo Michal, yes I can confirm issue is still there, after disabling Easy jQuery.

Also I need to mention that i have updated few ext. before Easy jQuery was activated, I will try to narrow it down, it is logical that something from those ext was in conflict.
Thats probably why I haven't seen this error before.

Zdravo Michal.
I have figured out what was the problem and with what JomSocial is having conflict, it is Kunena and Helix framework scripts i have implemented.
Earlier I had and issue with Kunena forum when I hover for example over icons they disappear after I remove mouse pointer from them, also with helix template with social icons in articles when hovered they disappeared until I refresh page.
I have solved this with custom javascript

window.addEvent('load', function() {
    $$("[rel=tooltip],[data-toggle],a[data-toggle],button[data-toggle],[data-toggle=collapse],a[data-toggle=dropdown]").each(function (e) {
        e.getParent().hide = null;
        e.hide = null;
    });
});

.hasTooltip {
    display: inline !important;
}

JQMIGRATE: Migrate is installed, version 1.4.1 jquery-migrate.min.js:2
JQMIGRATE: Migrate is installed, version 1.4.1 jquery-migrate.min.js:2 

I have fixed this Michal, you can mark this one solved.

Zdravo Goran.

Great to hear that ;)