Issue on "Customize" page


I have an issue when I go on Appearence -> Customize.
This is the only page I can see :

Can you help me ?

(I just installed GreatMag in a new installation of WordPress 4.7.5 and the only plugin I have is Page Builder by SiteOrigin).

And this is the url of the issue :

Hello @zendium,

Please make sure that your server meets WordPress requirements. You can contact your hosting provider support regarding this. And here you can find those requirements:

Please feel free to ask any other questions that you might have.

Kind Regards, Roman.