Shoutbox

I dunno if this might work, but disable the option to enhance the formatting toolbar then enable it again.

To do this if you're unsure, click "Plus!" at the top of your main contact list window.

Then click "Preferences", (then enter a password and click "Ok" if you set a password already).

Now click "Instant Messages" at the left, then make sure "General Options" has been clicked at the top.

Now find where it says "Enhance the formatting toolbar with  Messenger Plus! features."

If the box is already checked/ticked click on it to uncheck/untick it.

(If it isn't already ticked, then that's why it isn't showing, so you'll need to check/tick it.)

Now Click "OK".

Then repeat the other steps to get to the preferences and re-check/re-tick the box then click "Ok". (I would also exit msn then run it again.)