SimpleMachines.org
Why do I need it?A tool to repair some basic settings that may cause your forum to become inoperable. Simply upload to your SMF directory and ensure you delete this file after use.
Aside from its main purpose stated above, you will want to use it especially if you've converted from a different forum software (.e.g., phpBB2, IPB, vBulletin, etc.); or let's say that you've updated from an older version of SMF; or from my personal experience, I had to run this tool to fix some issues right after I transferred an existing SMF database from one webhost to another. repair_settings.php also checks specific things such as folder/file paths and configuration settings for databases. This tool may fix some common connection problem issues.
Where can I get it?
http://www.simplemachines.org/download/?tools
How do I install it?
Use an FTP client or the File Manager to upload the repair_settings.php file into the root directory of your SMF forum. For example, let's say the main directory of your forum is called "myForum" then you will want to upload the file into " mysite.com/myForum/ ".
How do I run it?
Just go to it like how you would visit any other site by typing in the proper URL. Using the same example above, you will want to go to " mysite.com/myForum/repair_settings.php ".
Credits
All credits go to the SMF development team and the author who created the tool. No need to thank me.