NouvelleVague

I'm building a shop on the cloud and can't access the backend anymore!! The screenshot attached is the message I'm getting when trying to access the shop. I can log in but when clicking ''manage my store'' can't go any further... The front end is still visible.

I'm new to prestashop and slowly starting to plow through tutorials and documentation, but having a problem with my navigation menu that's not horizontal... http://inuliflora.pswebstore.com/qc/ The menu items appear in 2 different places and both of them aren't horizontal... I installed the theme but it never looked like the theme's preview... Any guidance is welcome! Many thanks!