3DS:Error screens/Luma3DS exception screen

3DS:EXC

This page lists possible causes and fixes of Luma3DS exception screens. They are not applicable to every situation, but cover most common known issues.

Reading a Luma3DS exception screen

A Luma3DS exception has four (or five, in a few cases) different parts to it that help in finding its cause, as follows:

Processor: What part of the system is causing the exception. The two processors are:
- Arm9: The 'security processor' of the system. These exceptions usually result from errors in NAND data or hardware faults in either the 3DS or its SD card.
- Arm11: The 'userland' of the system. These exceptions have numerous causes but are often related to broken software or user data.
Exception type: How the system is causing the exception. These categories are often too broad to be helpful, but three of them are more precise:
- data abort: Oftentimes related to a broken mod or broken HOME Menu data. Occasionally related to custom firmware data being broken.
- prefetch abort (svcBreak): Oftentimes an issue with data on the NAND, even when Arm11. Can also happen when launching an out-of-region game.
- undefined instruction: Usually either a broken piece of software (if not on boot) or outdated boot.firm (if on boot).
Fault status: Why the system is causing the exception. Normally not helpful except for developers.
Current process: Where the error is coming from in the system. Often the most helpful part of the exception. Some examples of processes are as follows:
- fs: The filesystem, i.e. either the SD card or the NAND.
- menu: Data that is opened either as a part of the HOME Menu or at the same time as it.
- loader: The service that opens apps, meaning the app you last tried to open has an issue.
- nwm: Networking services, almost always WiFi.
R0: Usually just internal data that's not worth reading. There are two notable exceptions, however:
- Arm11 loader exception: If R0's contents start with a C or D, R0 is an error code. This code usually gives the exact cause of the issue.
- Arm11 pm exception: If R0's contents are E0E01BF5, boot.firm is guaranteed to be too outdated to work.

Known Errors

In the following lists, the file prefixes on file paths refer to the starting location. sdmc:/ refers to the SD card, and numbers in the format of [X:] refer to GodMode9's drive numbers.

If the below fixes do not solve your issue or you are unsure of what to do, join the [Nintendo Homebrew Discord] for further assistance.

Select which processor the error says it comes from.

Error On Boot

Exception Type	Problem & Solution
Any	Files on the SD are corrupted. To fix, verify that your SD card is not faulty. If it is verified working, make a backup of all intact files, format the SD card, and try booting again.
	A system save located on the NAND in `[1:]/data` has a problem.
	System-unique files are missing from the NAND in `[1:]/rw/sys`.
data abort	The `shared2` folder in `[2:] SYSNAND TWLN` is missing. To fix, create this folder.
data abort	System titles have been deleted. To fix, perform a Safe Mode update. If this does not work, perform a CTRTransfer.
prefetch abort (svcBreak)	The system movable, `[1:]/private/movable.sed`, is 288 bytes but a flag is enabled that expects a size of 320 bytes. To fix, boot into GodMode9 and select `SYSNAND CTRNAND`, then go into the `private` folder. Inside this folder, you will see a file named `movable.sed`. Select it, and under the options menu, select Show in Hexeditor. Green-colored numbers will appear in the middle of the screen - press `A` and then unlock writing to sysNAND (lvl2). At the beginning of the file, look for the set of numbers `53 45 45 44 00 01`. Once you find these numbers, hold `A` and press `D-PAD DOWN` while the `01` value is highlighted to change it to `00`. Press `B`, then `A`, then `B` to save changes and exit from the hexeditor, then press `START` to reboot your console.
prefetch abort (svcBreak)	`SYSNAND CTRNAND` has bad CMACs. To fix, press R+A on the `SYSNAND CTRNAND` drive and `Fix CMACs for drive`. The console will act like it has been formatted after this, and this is intended.
prefetch abort (kernel panic)	The console likely has a hardware issue.
undefined instruction	The console likely has a hardware issue.

Error During Use

Exception Type	Problem & Solution
data abort	Files on the SD are corrupted. To fix, verify that your card is not faulty. If it is verified working, make a backup of all intact files, format the SD card, and try again.

Error On Boot

Current Process	Exception Type	Problem & Solution
boss	data abort	The current firmware version is too old for SpotPass to work. Perform a Safe Mode update. If this does not work, you may require a CTRTransfer.
fs	any	Can be anything from SD card problems to hardware issues.
hid	any	Potential hardware problems.
ic2, spi	any	The console has a serious hardware issue that likely is not easily fixable. Join the Nintendo Homebrew Discord and ask, in English, for help.
mset	any	System Settings is broken in some way - this may indicate that the console has a hardware issue. To fix, perform a CTRTransfer, or a Manual CTRTransfer if that does not work. If neither of these work, the console has a serious issue. Join the Nintendo Homebrew Discord and ask, in English, for help.
menu	data abort	Broken HOME Menu theme. To fix, go into the folder `sd:/Nintendo 3DS/<ID0>/<ID1>/extdata/00000000/` and delete the folder matching your region, one of the following: USA: `000002cd` EUR: `000002ce` JPN: `000002cc`
		Broken HOME Menu extra data. To fix, go into the folder `sd:/Nintendo 3DS/<ID0>/<ID1>/extdata/00000000/` and delete the folder matching your region, one of the following: USA: `0000008f` EUR: `00000098` JPN: `00000082` KOR: `000000A9`
		Broken HOME Menu application. To fix, either perform a Safe Mode update, attempt to enter System Settings before the crash occurs and delete the application in Data Management, or reformat the SD card.
	prefetch abort	An installation of menuhax is conflicting with the custom firmware. To fix, place the `menuhax67_installer.3dsx` file from [this download] into `sd:/3ds`, run it through Homebrew Launcher, and choose REMOVE.
	prefetch abort (svcBreak)	The `f000000b` folder in `SYSNAND CTRNAND` is broken, its exact location being at `[1:]/data/<ID0>/extdata/00048000/f000000b`. To fix, backup `f000000b` by pressing R+A while highlighting it, then selecting `Copy to 0:/gm9/out`. Once it is backed up, delete the folder. If this does not fix the issue, copy the folder back where it was.
ns	prefetch abort (svcBreak)	The Luma configuration setting `Autoboot Homebrew` is set to boot to a title that does not exist. To fix, disable the option or install an application that matches the title ID set in `sd:/luma/config.ini`.
nwm	any	The WiFi chipset's hardware is damaged or dead. To fix, replace the WiFi chipset with a new one. To avoid the error until then, disable WiFi on the 3DS and do not turn it back on. If the 3DS is an old model, you can disable WiFi with an external switch. New models must instead disable it through the HOME Menu Settings or Rosalina. Repeatedly pressing the keycombo for Rosalina while powering on might let you access Rosalina before it can crash.
pm	undefined instruction	The installed version of Luma3DS likely does not support the current firmware version. This is guaranteed to be true if the contents of R0 are `E0E01BF5`. To fix, update CFW.

Error During Use

Current Process	Exception Type	Problem & Solution
3dsx_app	any	The `.3dsx` file you opened is corrupted. To fix, download a new copy of the `.3dsx` file. If this error happens when you open the Homebrew Launcher, download a new copy of `boot.3dsx`. If the error still happens, test your SD for errors.
app	any	The app you last opened has an issue of some kind. To fix, disable all game mods, cheat codes, and plugins to ensure they are not the cause. If the error still happens, then the game itself is likely faulty. If it is a cartridge dump, redump it. If it is an eShop game, click the Repair button at the bottom of its eShop page or delete and reinstall it. If it is a cartridge, clean the cartridge and the 3DS cartridge reader with isopropyl alcohol.
CtrApp	any	Broken system software is interfering with the app you last opened. To fix, disable all game mods, cheat codes, and plugins to ensure they are not the cause. If the error still happens, update from Safe Mode. If this does not work, perform a CTRTransfer.
GARDEN	any	Animal Crossing's game data or savedata is having issues. To fix, disable all game mods, cheat codes, and plugins to ensure they are not the cause. If the error still happens, then the game itself may be faulty. If it is a cartridge dump, redump it. If it is an eShop game, click the Repair button at the bottom of its eShop page or delete and reinstall it. If it is a cartridge, clean the cartridge and the 3DS cartridge reader with isopropyl alcohol. If the error yet still happens, ensure that you have not used a save editor before the error started happening. If it has been edited, you will need to restore a backup from before its use, or wipe the save and start over if you have no backup.
fs	any	Can be anything from SD card problems to hardware issues.
Kujira Joker niji_loc	any	The app you last opened has an issue of some kind. To fix, disable all game mods, cheat codes, and plugins to ensure they are not the cause. If the error still happens, ensure the game is the same region as the console - if it is not, force the game to use the correct region. If the error yet still happens, then the game itself is likely faulty. If it is a cartridge dump, redump it. If it is an eShop game, click the Repair button at the bottom of its eShop page or delete and reinstall it. If it is a cartridge, clean the cartridge and the 3DS cartridge reader with isopropyl alcohol.
loader	undefined instruction	The app you last opened has an issue. If the contents of R0 start with C or D, R0 is an error code. Most of the possible error codes for this are also listed on this page (WIP).
mset	any	System Settings is broken in some way - this may indicate that the console has a hardware issue. To fix, perform a CTRTransfer, or a Manual CTRTransfer if that does not work. If neither of these work, the console has a serious issue. Join the [Nintendo Homebrew Discord] and ask, in English, for help.
nwm	any	The WiFi chipset's hardware is damaged or dead. To fix, replace the WiFi chipset with a new one. To avoid the error until then, disable WiFi on the 3DS and do not turn it back on. If the 3DS is an old model, you can disable WiFi with an external switch. New models must instead disable it through the HOME Menu Settings or Rosalina. Repeatedly pressing the keycombo for Rosalina while powering on might let you access Rosalina before it can crash.
qtm cam	any	The camera's hardware is damaged or dead. To fix, replace the camera with a new one. To avoid the error until then, disconnect the camera or avoid using anything that activates the camera.