Error: Class “PHPMailer\PHPMailer\SMTP” not found

@michacassola, When do you see this error? SMTP Mailer seems to be working fine on PHP 8.1.13. Do you have the same plugins installed on your other website?

Hi, yes I have the same plugin working fine on other websites. This is the only one doing this. I get the error when using the Test Email tab.

2022/12/14 15:45:12 [error] 2375#2375: *19 FastCGI sent in stderr: "PHP message: PHP Fatal error:  Uncaught Error: Class "PHPMailer\PHPMailer\SMTP" not found in /var/www/domain.com/htdocs/wp-includes/PHPMailer/PHPMailer.php:1968
Stack trace:
#0 /var/www/domain.com/htdocs/wp-includes/PHPMailer/PHPMailer.php(2089): PHPMailer\PHPMailer\PHPMailer->getSMTPInstance()
#1 /var/www/domain.com/htdocs/wp-includes/PHPMailer/PHPMailer.php(2005): PHPMailer\PHPMailer\PHPMailer->smtpConnect(Array)
#2 /var/www/domain.com/htdocs/wp-includes/PHPMailer/PHPMailer.php(1664): PHPMailer\PHPMailer\PHPMailer->smtpSend('Date: Wed, 14 D...', 'test\r\n')
#3 /var/www/domain.com/htdocs/wp-includes/PHPMailer/PHPMailer.php(1502): PHPMailer\PHPMailer\PHPMailer->postSend()
#4 /var/www/domain.com/htdocs/wp-content/plugins/smtp-mailer/main.php(835): PHPMailer\PHPMailer\PHPMailer->send()
#5 /var/www/domain.com/htdocs/wp-includes/class-wp-hook.php(308): smtp_mailer_pre_wp_mail(NULL, Array)
#6 /var/www/domain.com/htdocs/wp-includes/plugin.p" while reading response header from upstream, client: 1.2.3.4, server: domain.com, request: "POST /wp-admin/options-general.php?page=smtp-mailer-settings&action=test-email HTTP/1.1", upstream: "fastcgi://unix:/run/php-fpm.sock:", host: "domain.com", referrer: "https://domain.com/wp-admin/options-general.php?page=smtp-mailer-settings&action=test-email"

• This reply was modified 1 year, 11 months ago by michacassola.

I am so sorry to have wasted your time!
It was my stupid noob mistake, I didn’t know I had anonther SMTP plugin installed, one that I didn’t use in years…
I will close. Sorry again!