If you are using encrypted ROMs, you must manually add the title keys to a file named keys.txt located in your Cemu installation folder.
A single hex code found in the console's OTP.bin that is required for general system decryption. cemu wii u title keys exclusive
Find keys.txt in your main Cemu directory or under %AppData%/Roaming/Cemu . If you are using encrypted ROMs, you must
Many modern Cemu users avoid title keys entirely by using game formats. If you are using encrypted ROMs
Specifically used for .wux and .wud disc images. Without these, Cemu cannot "read" the encrypted disc data. How to Use Title Keys in Cemu