Q: Trying to add a page to a pages document. It worked up to now but just finished page 13 with text and pictures and cannot add another page, Using macbook pro with El Capitan and latest version of Pages.

Have you placed your insertion beam at the very end of your page 13 text, and then apply Insert menu : Page Break? In Pages v5.6.2, I just added a new page to a four-page section with that approach.

Does your last document page prior to where you want to add a new page contain text, or various document objects (e.g. Text box, Shapes, Images, etc.)?

This is basic commonsense – which is as rare as hen's teeth!

We can not see what you are doing and what the result is, so YOU need to tell us.

Also don't say "the latest version of Pages". You may have got that wrong and no-one who reads this in a years time will know what you could be referring to. Say exactly what version you are using: Menu > Pages > About Pages

Just guessing, based on no other information, but I think you have filled the 13th page with objects and may be clicking in or on the objects because you have covered over the actual page text area. You need to have the cursor inserted in your text body.

You can do that if you click somewhere prior to the page and then move the cursor with the arrow keys forward through the text till you are on page 13 and then insert a Page Break or Section Break.

Peter