The phrase “clean ROM better” is a direct instruction from the error handler. In programming terms, “clean” means . “Better” suggests that your current ROM is inferior (incomplete). The system is refusing to run a half-baked DSi title.
If your ROM is definitely clean but the error persists, the issue is likely your setup. For those using TWiLight Menu++ on a 3DS or DSi, you may need to check your settings. Hold 'Select' while booting the menu to access the settings and ensure that the "DSi Mode" is enabled for games that require it. The phrase “clean ROM better” is a direct