CometChat issue - Online users not showing up

[XYZ500]

I know this isn't a CometChat support forum but I was wondering if there is anyone here who could maybe help me out with this. I also contacted CometChat support but they are going to take forever to reply. So I'm really hoping someone here could help maybe.

A couple of uses here blind-eddie and HM666 suggested me this so maybe they can help.

I bought Cometchat. I first did a test run on another vBulletin forum. It seemed to work. So I installed it on my actual vBulletin forum. It seemed to install correctly and everything I see on Cometchat seems to be okay. But here I am facing an issue that online users are not showing. It keeps showing 0 online users. I tried to login on another PC with another user account, but it still kept showing 0 online users. I don't know what's wrong. Does somebody here got any idea about this particular issue?

P.S. I am noticing that it has maybe broken the forum a little too. When I (or any user) tries to open private messages, a blank page comes up. Same case when somebody tries to make a post. I did a test run on another vB forum I have just to avoid any issues on my real site. Lol. My bad luck.