master pages missing

[Rosalie38555464r4t1]

Hi, 

So I wanted to edit some master pages in a new document. Usually, when you open the pages (Seiten) tab, it also opens a small window displaying all master pages. In this document however, it doesn't do that. Even if I close the tab and open it again, I can't find a display of my master pages (like in the small screenshot). It looks like the screenshot I've attached (large screenshot). 

Can yomebody help me with this problem? 

[leo.r]

Drag down this split bar to reveal the master pages:

Unfortunately, it doesn't look like a split bar so yes this UI is confusing.