We came across a ‘bug’ within WordPress recently that when creating a child theme of the theme “Twenty Thirteen” the drop-down selector within the Page edit screen (in dashboard) was not displayed. After a bit of playing about we managed to get the drop-down selector back.
If you are using a Child them with Twenty-Thirteen
Sometimes you are required to create a separate theme for your site for specific pages, for example if you want to display the content completely differently or in our case wanted to add some specific PHP code to work on only certain pages.
If you create your template file you would expect to FTP it to your Child theme folder. We have found that doing this creates the problem above, you will need to upload your template files to the main Twenty-Thirteen folder. Make sure you don’t name it the same as a file which is already there though!
After doing this the Template drop-down selector should now be in your Edit Page screen.