Mod Wii according to the following guide:

Be sure to install the IOS's in step D5

Install IOS56:

Use the following guide to download and install SoftChip only (other links are dead/give error):

Open SoftChip and use the following settings (do not insert game yet):
IOS 223 (use the + button to change)
Remove 002 Protection: Enabled
Load Requested IOS: Enabled

Press A, then insert game.
Try re-burning the game at 1x if this does not work.

Worked for me, hope it helps..