Video element disappears after page load in cornerstone content

[seffect]

After the last upgrade the video element shows for a second or two and then disappears when on a cornerstone page. I created two test pages, one without cornerstone:

—removed—

one with cornderstone:

—removed—

You can see how the video poster shows then goes away on the cornerstone page, yet on the non cornerstone page, where btw I copied the the tag exactly from the cornerstone page and just added a width, it works just fine. There is obviously a problem in the new cornerstone page framework for displaying videos. This breaks a few pages on our site.

EDIT: I discovered the conflicting javascript library from a marketing company, filename mtc.js, and I removed it and it video tags working again in cornerstone pages. It came from the company http://mediaelementjs.com/.

[christian]

Hey @seffect,

Glad you’ve found the conflicting script. It should be removed as MediaElement is already in WordPress. If it is being utilitzed in a third party plugin, please contact the developer regarding the conflict.

Thanks.