Make this test (I promise this is the last thing I’ll request you to do):
1) Make a backup of the .htaccess content
2) Remove this code from it & save the file:
RewriteCond %{QUERY_STRING} mosConfig_[a-zA-Z_]{1,21}(=|\%3D) [OR]
RewriteCond %{QUERY_STRING} base64_encode.*\(.*\) [OR]
RewriteCond %{QUERY_STRING} (\<|%3C).*script.*(\>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} GLOBALS(=|\[|\%[0-9A-Z]{0,2}) [OR]
RewriteCond %{QUERY_STRING} _REQUEST(=|\[|\%[0-9A-Z]{0,2})
RewriteRule ^(.*)$ index.php [F,L]
AddType application/x-httpd-php5 .php5 .php4 .php .php3 .php2 .phtml
3) Restore the plugin mod we did earlier so it looks like this:
// Register our TinyMCE Script
function add_tinymce_button_script($plugin_array) {
$plugin_array['YoutubeShortcodeMargenn'] = plugins_url('tinymcebutton.js.php?params='.$this->get_pop_up_params(), __FILE__);
return $plugin_array;
}
4) Test again the visual editor
If I’m right the Youtube button should appear.