Premium Press Page Builder – error!

Im using Premium press page builder plugin. When adding section or a row, the window opens but I have to scroll all way down to the bottom of the browser to access it (not visible in first screen). I can live with that, even though it should`t be like that ( it was ok in the beginning though).
Then when adding object, windows opens up in the same way (as explained above), I scroll down, and choose Headers – Jumbotron ( so far all the same). When choosing picture, (now the weird stuff happens), the media files (new window) shows up BEHIND the Object window and the screen freezes, with no possibility to access/click and choose the media/picture. I have to click on BACK button on the browser and the Result – No way to be able and build a page adding picture…

Why is this happening? Help please..:)

Niki