The fix is applied, but...
I noticed the message only because I knew it should be. Why not making it red, bold or elsehow more noticeable?
May be, it would be better to select the first page by default (and hide the list if no pages are available) instead of these warnings?
Also, when trying to move the last page down (or the first page up, or the first page in a submenu up, or the last page in a submenu down) nothing happens and no warning message is displayed.