So, I've been attempting for a half an hour now to figure this out. Never had a problem before now. So, after beating the elite 4 in kanto, all of a sudden the game won't let my sandslash use dig... It's the only pokemon I have that knows dig. Can someone help me?

Hey, RhyvurrGoRawr, this may be an issue of how much happiness your sandslash has. Dig requires 151 happiness to be used outside of battle (to shortcut caves and get dig patches). I'm guessing that because your sandslash fainted so much battling the elite 4, its happiness dropped below the 151 threshold. You can regain happiness by beating wild pokemon (+1 happiness) or leveling up (+4 happiness). You can also check how much happiness you have using /happy 1-6 depending on the slot number the pokemon is in your party. Good luck!