Troubleshooting
Unlaunch
Unlaunch freezes at MISMATCH IN FAT COPIES
twlnf has a critical bug where it does not properly update the entire NAND after modifying it, which causes certain homebrew (like the Unlaunch installer) to throw an error.
To fix this, open NAND Title Manager (NTM), and select Fix FAT copy mismatch.
There is no audio or boot splash when launching "Launcher" using Unlaunch
The developer of Unlaunch (nocash) has intentionally patched out the background audio and boot-splash by default. You can regain these effects by reinstalling Unlaunch with Enable sound and splash turned on, or by using hiyaCFW.
Powering on only shows a black screen after installing Unlaunch
Try ejecting the SD card and powering the console on again. If it still only shows a black screen, you may need to flash your NAND via either ntrboot or a hardmod.
Powering off in the DSi Menu and/or System Settings takes 5-10 seconds
The only solutions are starting the DSi Menu and/or System Settings with the SD card ejected, installing hiyaCFW, or uninstalling Unlaunch.
After installing Unlaunch, I'm stuck booting into an application or the Unlaunch Filemenu
This was likely caused by choosing the wrong app for the NO BUTTON option in Unlaunch. Hold A + B while starting the console, go to OPTIONS, and set NO BUTTON to whatever your preference is.
Other Unlaunch problems
If Unlaunch displays Clusters too large, Bad VBR, Bad MBR, or doesn't display any applications while the SD card is inserted, your SD card likely wasn't formatted correctly. Re-follow SD Card Setup.
TWiLight Menu++
For general TWiLight Menu++ troubleshooting, see its FAQ & Troubleshooting page on the DS-Homebrew Wiki.
Further assistance
If you have encountered an issue that is not solved here, or one that persists despite the given solutions, ask for assistance in the DS(i) Mode Hacking! Discord server.