Error in console

Hi Support

Since last update, I encounter a strange error in my console, which prevent a background image to be displayed in the page quoted below.
The error besign by

Header always set Strict-Transport-Security "max-age=300; includeSubDomains; preload"</script> <link rel="profile" href="http://gmpg.org/xfn/11" /><link rel="alternate" type="application/rss+xml"

I’m using a child theme, but the error occured even if I engage the enfold parent theme
With or without plugin : same result
It may have something to look with Apache configuration, but I’ve haven’t change anything (and I a share hosting anyway).

Thanks for your help !