The error message:
Intrusivo 70 http://site.com/wp-admin/admin-ajax.php Failed to load resource: the server responded with a status of 500 (Internal Server Error)
This error says two things:
a. server responds with status 500
Please contact hosting to confirm what that means.
b. JS error in wordpress files (wp-admin/admin-ajax) That is wordpress file and if wodpress errors show can be several causes (but it’s not theme for sure as for us everything works fine)
Solution:
This is related to the server configuration.
To solve it – install php5-url (original link with the solution) https://wordpress.org/support/topic/plugin-ajax-fo…