"iZap video" plugin conflict with "file" plugin thumbnail

I want to share my experience. I solved the no thumbnail image error for uploaded file, after installing iZap Video plugins. I used the plugin iZap video https://elgg.org/plugins/384975 and elgg version is 1.11.4.

After install iZap Video,that is working properly. File upload is working properly. But no thumbnail image in file. I commented out the following lines at elgg/mod/izap-videos/start.php .

#       else {
#               global $IZAPSETTINGS;
#               $url = $IZAPSETTINGS->graphics . 'no_preview.jpg';
#               $url = elgg_trigger_plugin_hook('file:icon:url', 'override', $params, $url);
#               return $url;
#             }

Line 356 to 361

And thumbnail image back. Please let me know if i am wrong.

Thank you all, elgg and all plugin creators.

(sorry for bad english)