Hey there,

I am really sorry for the delay of this reply as it is a weekend for us here.

Regarding with your first issue : (composer blank page)
>> Because from this "Easyblog(dashboard)- composer " menu, you didn't assign one of category inside the menu, so causing this issue. I already help you select one of the default category, it should work fine now.

Regarding with your second issue : (Facebook didn't get any info from the blog post)
>> The reason why you hitting this is because public user can't view your post.
>> For example : when I view this post https://celex.com.br/index.php/celex-talk/empresas-em-algum-momento-e-preciso-abrir-os-olhos without login, your site will ask me to login first.
>> It actually same as Facebook or Linkedin, when the Facebook/ Linkedin trying to retrieve this post content from the page, but they do not have the permission to access it, so it show nothing from the result.
>> To fix this , you have to set everyone also can able to access your single post.

Hope this help.