SOLVED – YouTube or Other Videos Not Embedding in Wordpress MU Posts
If you are a Wordpress MU administrator and getting complaint that your users are not able to upload or embed YouTube videos or any other video in posts then here is the solution to do that. In Wordpress MU, when you will try to embed the code of YouTube video, it will disappear after hitting the ‘Publish’ button. To embed YouTube video or any other video, you will have to make some code changes in Wordpress MU file.
In Wordpress MU setup, under ‘wp-include’ folder, you can find ‘kses.php’ file. You will have to edit that file to enable YouTube or Other videos embed feature in Wordpress MU posts. Open ‘kses.php’ file on editor and make the below changes into that file. First of all try to find the code (in black color) on kses.php file. These changes will enable your Wordpress MU editor to embed videos like YouTube and Vimeo.
After the below piece of code;
'ol' => array ( 'class' => array (), 'start' => array (), 'style' => array (), 'type' => array ()),
Add the below mentioned code,
'embed' => array ( 'style' => array (), 'type' => array (), 'id' => array (), 'height' => array (), 'width' => array (), 'src' => array ()), 'object' => array ( 'height' => array (), 'width' => array ()), 'param' => array ( 'name' => array (), 'value' => array ()), 'object' => array( 'width' => array (), 'height' => array (), 'movie' => array (), 'allowFullScreen' => array (), 'embed src' => array(), 'application/x-shockwave-flash' => array()),
Save the ‘kses.php’ file and upload it to your server. Now you can embed a video (for example YouTube) code and publish the post. Now your post will show the newly embedded video in proper way. You may add other type of media tags to add them in your posts on MU.



This is very useful post for me. Actually many time i tried to add video from youtube but could not. Here i got the perfect solution. Thanks buddy.
Why does WP MU not come out with that already done? Just asking as I know many don’t like editing WP files, to afraid to make the change and then they have to edo the change when a new version comes out.
This looks great, thanks–but I’m wondering what happens when it’s time to upgrade MU. Do we have to re-upload this file every time we upgrade?
Its dangerous coz this code allow XSS!
I’ve been looking at downloading videos from YouTube, it seems that YouTube and many other social network sites have changed their code in order to prevent certain sites from allowing you to download video content from them; most annoying, is there a foolproof alternative? Anyway, excellent blog post, I found it very insightful
Sorry, this is NOT recommened. Do not hack the core, when there are plugins to do this for you.
Also, new in 2.9.1 video embeds are built in and enabled for MU.