Hello. Thank you for contacting the Toolset support.
Can you please share admin access details as well as share details about where you added the code you shared and let me review the settings and get back to you.
*** Please make a FULL BACKUP of your database and website.***
I would also eventually need to request temporary access (WP-Admin) to your site. Preferably to a test site where the problem has been replicated if possible in order to be of better help and check if some configurations might need to be changed.
I have set the next reply to private which means only you and I have access to it.
It does not seem to be Toolset issue as the cornerstone video field requires Embed code and you just added the video URL to it.
=> hidden link
Either you should upload the video you have to youtube.com and then get the embed code and add the embed code to the video field or you can use the following code: