Webmail Login stuck on "Logging you in ...".

Symptoms

When clicking the "Check Email" button in cPanel, the login gets stuck spinning, similar to the screenshot below.

An entry similar to the following is also present in "/usr/local/cpanel/logs/php-fpm/error.log".

WARNING: [pool user_username] server reached max_children setting (25), consider raising it

Description

This issue occurs when the cpanel_php_fmp service hits the max_children limit. This limit can be temporarily increased per user or globally. The limit increase is temporary because changes to the cPanel user's configuration file will be lost upon reboot, and changes made to the global template file will be overwritten when cPanel updates.

Workaround

1. Access the server's command line as the 'root' user via SSH or "Terminal" in WHM.
2. Open the relevant file in your preferred text editor.
   • Per user

     /var/cpanel/php-fpm.d/$username.conf

     Please note that "$username" must be replaced with the username for the cPanel account.
   • Globally

     /usr/local/cpanel/src/templates/cpanel_php_fpm/user.default

3. Set "pm.max_children" to a value greater than 25
4. Save the changes and exit the text editor.
5. Restart the cPanel PHP-FPM service to apply the changes:

   /scripts/restartsrv_cpanel_php_fpm