The Edit in context toolbar is greyed out and not responding.
The edit in context editor is not in focus. The editor's toolbar is active only when the editor is in focus.
When a user clicks away from checked-out content, the toolbar remains in place but becomes opaque. It is an indication that the content is checked out but inactive.
In general, if the toolbar is greyed out, users need to click the content to activate the toolbar. In Internet Explorer, users must click the content twice. The first click selects the object. The second sets the focus to the object.