Posible conflict detected

NGFB Warning :
Possible conflict detected – Your theme or another plugin is adding a link rel=”author” HTML tag to the head section of this webpage.
NGFB Warning :
Possible conflict detected – Your theme or another plugin is adding a meta property=”article:author” HTML tag to the head section of this webpage.
NGFB Warning :
Possible conflict detected – Your theme or another plugin is adding a meta property=”og:title” HTML tag to the head section of this webpage.

This appear from some time now, when i publish an article or edit. But Whi show me this error?
Everthing functioning well, but appear all yime this with red!

https://wordpress.org/plugins/nextgen-facebook/