Instant messaging won't pop out anymore

I have been having a problem with Jitsi for over a week now, I have been trying to enter my office Instant Messaging chat room and the pop out chat box doesn’t come up. I shows that I have entered the chat to all my team mates but I am not able to see the chat. I also do not have access to any individual chats either including Instant message, video chat, etc. Can anyone help me on what to do to fix the problem?