Prod Keys Not Working — Every Error and Its Fix

Most prod keys problems are one of five situations, and the emulator usually names the one it is in. Match the message rather than reinstalling everything at once.

Diagnosis by message

Message	Cause	Fix
Keys not found, no keys loaded	File invisible to the emulator	Keys not found
Invalid prod keys	File is truncated, repackaged or has the wrong content	Validate the file
Failed to decrypt NCA	Keys older than the game	Current release
Game requires a system update	Firmware too old	Firmware too low
Worked yesterday, fails today	A game, firmware or emulator update changed the generation	Version history

The two checks that fix most cases

1. The real file name. Windows hides known extensions, so prod.keys.txt displays as prod.keys. Enable file extensions or rename the file explicitly.
2. A full restart. Keys are read once at startup. Reloading a game inside a running emulator does not pick up a new file.

When the file looks right

Then it is a generation mismatch, not a placement error. Confirm the key generation in your file against the firmware generation you installed — a mismatch between the two produces decryption failures that look like corrupt keys. Firmware vs prod keys shows how to tell which side is wrong.