Note: This documentation is for Moodle 2.7. For up-to-date documentation see error/admin/cronerrorpassword.

error/admin/cronerrorpassword

From MoodleDocs

If this page is displayed you have attempted to force cron from your browser but have not appended the password set in Cron Password for remote access in Site Policies > Security e.g. http://site.example.com/admin/cron.php?password=opensesame.