Also remember that while downloading the wad manager, the wad manager folder is copied to your apps folder and the dol file in your wad manager folder is renamed as
The link for the masterquest wad is given here: VC_Zelda Oo TMaster Quest2Lang NTSC_Wii U Emulator Download torrents with working Emulator and Homebrew.
If it still doesn't work, find a brighter light and look again; you may have missed something. If it's a game you just bought, try exchanging it where you bought it.
Otherwise, you can try polishing out the scratch; there's a good instructional article on dealing with scratches at Wiki How.
Before you throw the disk in the trash or the console out the window, here are a couple of things that might get you back to playing games.