LinkedIn Sharing Blocked

I try to share a blog post on http://www.theworldsgreatestbook.com using Sharexy or the share button from JetPack. I get no link preview image and in the description box, it says:

Forbidden

theworldsgreatestbook.com

You don’t have permission to access /pubml-web-based-ebook-format/ on this server. Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request. Apache/2.2.27 (Unix) mod_ssl/2.2.27…

Something appears to be blocking open graph data. I went in to htaccess and even tried deleting the entire ban list, but that didn’t help anything. Several sites reference bots to delete but some of the recommended ones don’t even appear on the list, and some of the instructions refer to old Better WP Security plugin. Most of my traffic depends on LinkedIn sharing. If I (or my readers) can’t share links, I’m dead in the water. And based on a search, I’m not the only one having this problem.

Please help. I am launching a new publishing product and my #1 marketing engine is crippled.

https://ww.wp.xz.cn/plugins/better-wp-security/