Hi Yves,
Thanks for reaching out with your BoldGrid Post and Page Builder for WordPress questions. I’m sorry to hear you’re having a bit of trouble but let’s see if we can help you out!
I tried inspecting the first URL but it seems to be generating an error of some sort. I was, however able to review the second URL and my major suggestion here is, if you’re planning on using the Post and Page Builder as your primary page builder you should consider switching to a BoldGrid theme such as Crio Pro WordPress theme for compatibility purposes.
Crio comes out of the box with over 400 fully featured customizable options. I see you don’t have much content on the second URL now so if you were to make this change I think now would be the best time.