Queue not sending email

I installed GD-mail Queue plugin because wp-foro became very slow when I posted a new item on the forum or when users were sending a reply. This plugin works fine when sending emails, but WP foro was still very slow. When testing the email queue all my mails stay in the queue [~1 second (5minutes interval)]. I checked the Cron job with “WP Crontrol” plugin becaus apparently the cron job wasn’t started. I saw this topic already was on this Forum 3 years ago and tried the proposed solution. Hello, You need to check the wp-config.php for this line: define(‘DISABLE_WP_CRON’, true); and change it to define(‘DISABLE_WP_CRON’, false); or add it if it is not there. Then the cron will run. By changing the config.php with Filezilla my site crashed and I had to replace the config.php with the old one. Do you have a solution for this. Kind regards, Theo