Jose Castaneda on "wp-includes/formatting.php - where is it to resolve htmlspecialchars() warning"

In the Pinnacle theme, the home page header graphic has this waing where the "Welcome" message should be:

Waing: htmlspecialchars() expects parameter 1 to be string, array given in /home/content/69/6454569/html/IMARRIEDTHEWAR/wp-includes/formatting.php on line 3582

I cannot locate the wp-includes/formatting.php file in the editor. Where can I find this file and how can I remove the waing?

Or is this possibly an issue that needs to be solved with the WordPress host?

Thank you.

Hi there!

Have you tried deactivating all your plugins?