PHP Fatal error: Allowed memory size of X bytes exhausted (tried to allocate X bytes) on WordPress Admin Dashboard

Symptoms

• Plesk panel shows the following error when opening Domains > example.com > WP Toolkit > Log In (Dashboard)

PHP Fatal error: Allowed memory size of X bytes exhausted (tried to allocate X bytes)

Cause

Configuration in wp-config.php restricts available memory for scripts execution

Resolution

1. Connect to the server via SSH

2. Open file /var/www/vhosts/example.com/httpdocs/wp-config.php with any text editor, vi for example, and find memory_limit option

3. Increase memory_limit to fulfill application requirements:

@ini_set( 'memory_limit', '256M' );