Sorry if it's not the right place to post that but I did not find better.
I know in Wordpress, it's possible to restrict users to change pages or remove items from the menu.
But is it possible to restrict them to change a content in a page? As I am using Visual Composer I think this feature may be related to this.
I did find there is a role manager page with Visual Composer but the configuration isn't deep enough to have that level of restriction.