Check here on how to update TWiLight Menu++:
Bug fixes
- Fixed an issue caused by a devkitARM (and libnds?) update, where opening the DS Classic Menu on DS flashcards would cause TWLMenu++ to crash and restart.
- 3DS/2DS users: Updating via Universal-Updater now works again.
- Note that you'll no longer be able to update TWLMenu++ and nds-bootstrap nightly builds, due to the TWLBot account being made private.