The "My Page Order" plugin is no longer functioning. There is reason to hope for a fix, but in the meantime, you can set the page order manually. Go to Pages > Edit to see a listing in order of all your pages. Hover over the title of a page whose order you want to adjust and choose "Quick Edit." Then increase or decrease the number in the "Order" field as needed. You may need to adjust multiple pages to get the order you desire.