Disable upgrade notification and prevent upgrade Mautic by another user from web. Try more stable console upgrade (read bellow)
- Download security_local.php script https://gist.github.com/kuzmany/3b47f2427d470f4a51e99552063ce04e
- Copy security_local.php to app/config/
- Clear cache (remove app/cache/prod/ directory)
How to upgrade with console
If you are have access to SSH, we highly recommend that you use the update script. Download it to the root of your Mautic installation and run it from SSH/CLI with php upgrade.php.
php upgrade.php
If you are on a VPS, be aware of the user used to execute that command as you may have to fix the owner to be that of your web user. Be sure to remove this file once the upgrade is complete.