Yorum yaptığım zaman "Sitenizde ciddi bir sorun çıktı." hatası alıyorum.

Tema değiştirdim, eklenti kaldırdım. Sorun hala devam ediyor. Nasıl çözüm bulabilirim

Error log kayıtları

[30-Dec-2024 20:22:55 UTC] PHP Fatal error:  Uncaught Error: Call to undefined function PHPMailer\PHPMailer\mail() in /home//public_html/wp-includes/PHPMailer/PHPMailer.php:880
Stack trace:
#0 /home//public_html/wp-includes/PHPMailer/PHPMailer.php(1968): PHPMailer\PHPMailer\PHPMailer->mailPassthru()
#1 /home//public_html/wp-includes/PHPMailer/PHPMailer.php(1691): PHPMailer\PHPMailer\PHPMailer->mailSend()
#2 /home//public_html/wp-includes/PHPMailer/PHPMailer.php(1523): PHPMailer\PHPMailer\PHPMailer->postSend()
#3 /home//public_html/wp-includes/pluggable.php(546): PHPMailer\PHPMailer\PHPMailer->send()
#4 /home//public_html/wp-includes/pluggable.php(1862): wp_mail()
#5 /home//public_html/wp-includes/comment.php(2417): wp_notify_postauthor()
#6 /home//public_html/wp-includes/class-wp-hook.php(326): wp_new_comment_notify_postauthor()
#7 /home//public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#8 /home//public_html/wp-includes/plugin.php(517): WP_Hook->do_action()
#9 /home//public_html/wp-includes/comment.php(2348): do_action()
#10 /home//public_html/wp-includes/comment.php(3700): wp_new_comment()
#11 /home//public_html/wp-comments-post.php(25): wp_handle_comment_submission()
#12 {main}
  thrown in /home//public_html/wp-includes/PHPMailer/PHPMailer.php on line 880