3DS:Error screens/Luma3DS exception screen

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.
 * 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 * undefined instruction: Usually either a broken piece of software (if not on boot) or outdated  (if on boot).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. Common or unique processes are as follows:
 * fs: Files on your SD card or NAND are having issues.
 * hid: Potential hardware problems.
 * menu: Some of the data/extdata that's either associated with the HOME Menu or loaded at the same time is broken.
 * pm: Almost always,  is too outdated to work.
 * loader: The app you last tried to run has an error.
 * qtm/cam: Your camera has a hardware issue.
 * nwm: Your WiFi chip is damaged, dying, or entirely dead. This always means you must disable WiFi to stop the errors.
 * 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 * Arm11 pm exception: If R0's contents are,   is guaranteed to be too outdated to work.

Known Errors
Note that the prefixes on file paths refer to the starting location. refers to the SD card, and numbers in the format of  refer to GodMode9's drive numbers.

On boot

 * 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 booting again.
 * A system save located on the NAND in  has a problem.
 * System-unique files are missing from the NAND in.

Prefetch abort (svcBreak)

 * The system's movable,, is 288 bytes but its flag indicates otherwise.
 * has bad CMACs.
 * To fix, press R+A on the  drive and  . Your system will act like it has been formatted after this, and this is intended.

Data abort

 * 's  folder is missing.
 * To fix, create this folder.
 * System titles have been deleted.
 * To fix, perform a Safe Mode update. If this does not work, perform a CTRTransfer.

During use

 * 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.

boss (0004013000003402), data abort

 * The current firmware version is too old for SpotPass to work.
 * To fix, perform a Safe Mode update. If this does not work, you may require a CTRTransfer.

fs (0000000000000000)

 * Can be anything from SD card problems to hardware issues.

hid (0004013000001D02)

 * Potential hardware problems.

menu (000400300000__02), data abort

 * Broken HOME Menu theme.
 * To fix, go into the folder  and delete the folder matching your region, one of the following:
 * USA:
 * EUR:
 * JPN:
 * Broken HOME Menu extra data.
 * To fix, go into the folder  and delete the folder matching your region, one of the following:
 * USA:
 * EUR:
 * JPN:
 * KOR:
 * Broken HOME Menu application.
 * To fix, perform a Safe Mode update.
 * If this does not fix it, attempt to enter System Settings before the crash occurs and find the broken application in Data Management, if possible.
 * If this does not fix it, you may try to enter GodMode9 and use its title list to find the broken application - this is risky, however, and should not be attempted without guidance unless you know exactly what you are doing. For guidance, join the [Nintendo Homebrew Discord].

menu (000400300000__02), prefetch abort

 * An installation of menuhax is conflicting with your custom firmware.
 * To fix, place the  file from [this download] into , run it through Homebrew Launcher, and choose REMOVE.

menu (000400300000__02), prefetch abort (svcBreak)

 * The f000000b folder in  is broken, its exact location being at.
 * To fix, backup that folder by pressing R+A while highlighting it, then select . Once backed up, delete the folder. If this does not fix the issue, copy the folder back where it was.

pm (0000000000000000), undefined instruction

 * The installed version of Luma3DS does not support the current firmware version.
 * To fix, update CFW.

loader (0000000000000000)
If the hexadecimal number next to R0 starts with 'C' or 'D', search for it as an error code or in 3DS:Error_screens/Luma3DS_ErrDisp. These errors are usually due to corruption, such as a faulty/dirty SD card or game cartridge.