get_current_theme is deprecated since version 3.4__Error!!

Hi, I get an error as follows:
get_current_theme is deprecated since version 3.4! Use wp_get_theme() instead. in /home/***/public_html/****.com/wp-includes/functions.php on line 3378

I did open the functions.php file in that location, but I couldn’t find the “get_current_theme” function anywhere. The error just appeared out of nowhere. The site was working fine before. No updates or new plugin/theme installs were performed before this error appeared.

I did try disabling all plugins, and resetting to the default theme. Is there any way to fix this without a fresh new install?