So I found out, that the id for creating the metabox is allready taken by annother one…
in the admin_menu.php it should not be “myplugin_sectionid”
add_meta_box('myplugin_sectionid', 'Disable Wpdevart facebook comment',array($this,'generete_html_for_wpdevart_comment_box'), $post_type );
But when I change it to a uniqe one, I get following error in the insertet box below:
Warning: call_user_func() expects parameter 1 to be a valid callback, function ‘generete_html_for_wpdevart_comment_box’ not found or invalid function name in…
Any advice?
