If you need prod.keys for firmware 14.1.2, you must have access to a Nintendo Switch that is:

In the context of Nintendo Switch homebrew and emulation, (production keys) are essential cryptographic files used to decrypt game data and firmware. Version 14.1.2 refers to the specific set of keys required to match the Nintendo Switch system firmware 14.1.2 released in mid-2022. Overview of Prod Keys 14.1.2

: It addressed minor system bugs, ensuring smoother decryption for certain titles.

This happens if your prod.keys are from an older firmware (e.g., 13.0.0) but you are trying to run a game that requires 14.1.2. You must re-dump the keys after updating your console.