hi, can you tell me what does mean this error code 0xFFFFF825 ?
try to decrypt the game with Cdecrypt or JNUSTool and see if there's any issue, like incomplete .app, or checksum issue while decrypting, etc.
redownload the bad .app file
if you use WiiU USB Download helper program, it will check your downloaded files while downloading the game to be sure they are good. (it decrypts them temporarily in memory in background to see if all can be decrypted correctly)
If not, like I said you can try with Cdecrypt, or JNUSTool to decrypt the .app manually and see if you get any errors.
Sorry if the question is dumb or already answered but I have the 3 Mario Kart DLCs already installed, they work fine with the game disc. If I install the game on the internal memory with wupinstaller, will they still work? (I'd like to avoid using a cfw to use my payd DLCs if possible)
Thanks a lot!