I tried all of the mentioned solutions. It is possible to run the “Lite” version. It works as expected.
When trying to install the “Pro” version (1.5.2)
I get this error:
Fatal error: Cannot redeclare class WordPress\Plugin\Encyclopedia\AJAX_Requests in /home/content/94/8672194/html/wordpress/design/wp-content/plugins/encyclopedia-pro/classes/class.ajax-requests.php on line 3
It could be that the error is thrown because I have both of the plugins. When I de-activate and delete them both and try to install the “Pro” version alone, the problem persists. It seems to be installed, but is not shown in in the menu.