W3C Error

Hello,

i have a W3C Error on attachment sites:
“Duplicate attribute title.”

In the HTML code it is like this:

<p class="attachment"><a title="Kommentar Fehler mit Layout"  href='https://www.all4hardware4u.de/wp-content/uploads/2015/03/kommentar-fehler-design.png' data-rel="lightbox-gallery-FEVf" title=""><img width="558" height="343" src="https://www.all4hardware4u.de/wp-content/uploads/2015/03/kommentar-fehler-design-558x343.png".....>

So there is a second attribute title and this is empty. This behavior is only on an attachment site like https://www.all4hardware4u.de/programmierung/codeschnipsel/kommentare-in-wordpress-vor-absenden-pruefen/attachment/kommentar-fehler-design/ and not on the “normal” sites.
How could this be fixed? Somewhere in the settings anything to change that no link change is made by the plugin (wp_get_attachment_link) on attachment sites? Or will be it fixed in the next update?
At the moment i remove the empty title-attribute via jQuery.

Best regards,
Harry

https://ww.wp.xz.cn/plugins/responsive-lightbox/