>>29199928>>29199868I found it.
In case anyone is also having trouble with Steelhax:
1. Launch Steel Diver, select a Mii, close the game.
2. Run homebrew, run the steelhax installer
3. Run Steel Diver. It'll tell you that corrupted save data has been deleted. DO NOT PRESS OK.
4. Run homebrew again, run the steelhax installer again.
5. Return to your home menu and run Steel Diver.