This is a bug that occurs from time to time when creating a PM. There are a couple of things to try when this happens. 1. Refresh the page from which you are launching the PM. Not just press the PM button again, but refresh the page that has the button. 2. Press the Horizontal Rule button on the formatting toolbar. This can force a horizontal rule character into the chat area and force it to display the typing area. You can leave it there, or delete it with an edit when you are done.
