Yannis Despotopoulos

Thanks for your replies.

I tried with another public server and I get the text area! 

But how can a server prevent me (the client) from opening the chat ?

I asked the server admins to check their logs, but they did not see anything strange. What should I ask the server admins to fix or check?

It used to work, because I could /login to that server one week ago!

I changed the chat from t to m , still does not work!!

Other shortcuts work, like l which shows the Advancements

I also attached the options menu for chat, which is enabled.