Marketpress trouble in paradise ..

Hi there,
One of my site's has a conflict with Marketpress. When I enable this plug-in I can't edit the E-newsletter, or start a new post/article (pages stay white when marketpress is enabled) and a weird menu(mobile menu from the theme) is on the front-page. Before it worked just fine.
The theme is Vantage - paid version (
The site is
You have access through the plugin.

Ty for reading :slight_smile: