It’s time to upgrade the Mantis Bug Tracker installation. What is Mantis BT? From their website https://mantisbt.org:

MantisBT is an open source issue tracker that provides a delicate balance between simplicity and power.

I use it to keep track of the issues of all my projects. It keeps me sane.

Here are the steps that I took to upgrade:

• Download the new Mantis BT version.
• Upload to your server under a new folder. For me, it’s “mantisbt-new”.
• In your current Mantis BT folder copy mantis_offline.php.sample to mantis_offline.php. This will enable maintenance mode which prevents from users modifying the data while a database migration is ongoing.
• Back up database. Always try to prepare for the worst.
• Go to http://<your site>/<your new Mantis BT folder>/admin/install.php
• Enter the needed database information and proceed.
• Edit the config_inc.php file of your new installation as needed (mantisbt-new)
• Rename your Mantis BT folder to something else. I renamed mine to “mantisbt-old”.
• Rename your new Mantis BT folder (mantisbt-new) to your Mantis BT working folder (mantisbt)

That’s it! You’re now running v2.22. Don’t forget to delete your previous installation.