Line tool - can't edit once the line is drawn

I opened the program this morning and I all the sudden can't edit a line once it is drawn with the line tool. It is not showing the center point of a line or the open boxes at the ends of the line - I get solid looking boxes and not center point. The only way to move it is to go to the selection tool. It will not let me edit the actual line at all. How do I get editing back?

Thanks!