Problem with w3c validator

I just discovered that w3c complains about many errors caused by iframe attributes:

Bad value 100% for attribute width on element iframe: Expected a digit but saw % instead.

webkitAllowFullScreen mozallowfullscreen allowFullScreen></iframe> </div>

Attribute webkitallowfullscreen not allowed on element iframe at this point.

See it here:

http://validator.w3.org/check?uri=http%3A%2F%2Frud.clickon.ch%2F&charset=%28detect+automatically%29&doctype=Inline&group=0&user-agent=W3C_Validator%2F1.3+http%3A%2F%2Fvalidator.w3.org%2Fservices

any clue how to fix it?

https://wordpress.org/plugins/fluid-video-embeds/