This button allows you to reset mod config. Basically it deletes all cheatutils related config files, and prevents from recreating them in current session. You have to manually exit Minecraft after this. If you have some useful configurations or scripts, you can backup config files manually by copying them from config directory inside your Minecraft installation. You can also delete config files manually if you want.
Remember to always restart Minecraft after this, so mod will start with fresh config.
"Reinstalling" mod can't fix any problem. Mod JAR file is static and never changes.