Description

The DSi immediately boots to "an error has occurred."

This can happen if the installed WiFi module and firmware are incompatible.

Solution

If you have the DWM-W015 WiFi module, the error is caused by something else. The DWM-W015 version is compatible with all firmwares.

If you have the DWM-W024 or J27H020 WiFi modules, you will need to either replace them with a DWM-W015 or upgrade your firmware to v1.4 or higher.

Alternatively, you could only update the WiFi firmware in NAND. Download the latest WiFi firmware with NUSGet and copy the app and TMD to the following directory as "000000xx.app" and "title.tmd".
  NAND:/title/0003000f/484e4341/content/

Note: you must enable "create decrypted contents" in NUSGet.

You can back up your non-working NAND and restore the fixed one through ntrboot.

The WiFi module types are shown below. From top to bottom: DWM-W015, DWM-W024, J27H020