Need Help with homebrew

[Rybamar]

I'm trying to access the audio files of YGO Zexal World Carnival (It's a japanese rom)

I tried using pack hack to dump the files of the rom and it was a success. But when I tried extracting the romfs.bin I found myself with:

PS C:\3dstool> .\ctrtool -t romfs --romfsdir=romfs DecryptedRomFS.bin
[ctrtool::RomFsProcess ERROR] RomFsHeader is corrupted.

I have no clue of what to do now so any help or suggestion will be very much appreciated

Also when I tried using 3dstools to extract DecryptedRomFS.bin it always said "the file is a missmatch" for some reason