From Online Manual
repair_settings.php is one of the most important tools for use with SMF. It allows you to change the most important settings such as MySQL information, file paths and urls, and can be used when SMF is not working at all. That is what it is mostly used for: repairing your SMF enough so that an admin user can login and fix any other problems.
Using repair_settings.php is easy: simply upload the file to the root directory of your forum with FTP and then access the page in your browser. Once you have finished, remember to delete the file or else you will leave your forum vulnerable!
This tool can repair the following settings:
- Critical Settings
- Maintenance Mode - You can turn maintenance mode on your forum on and off and also make it completely unusable.
- Language File - Change the language of your forum.
- Cookie Name - Change the name of the cookie that your forum creates for the user's browsers.
- Queryless URLs - Turn the use of queries in the forum's urls on and off.
- Output Compression - Can turn output compression on and off.
- Database driven sessions - Can set whether sessions are managed by the database or not.
- MySQL Settings:
- Includes all of the typical settings that are needed to connect to the database; MySQL server address, MySQL database name, MySQL username, MySQL password, and MySQL table prefix.
- MySQL connection type - Can be set to Persistent or Standard.
- Paths & URLs
- Allows you set set the paths for; Forum URL, Forum Directory, Sources Directory, Attachment Directory, Avatar URL, Avatar Directory, Smileys URL, Smileys Directory, Default Theme URL, Default Theme Images URL, and Default Theme Directory.
Recommended values In most cases, SMF can detect the correct value for each of the fields and settings. Underneath many of the settings is a link with with the recommended value. Clicking these links will update the corresponding textbox fields with the recommended value. Be careful though, because SMF will not always guess correctly if the server is configured unusually.