I bought a brand-new MacBook Air and can't finish setting up Touch ID. When the setup window asks for my Mac password, the password field shakes as if the password is incorrect. However, the same password works when unlocking the Mac and approving other prompts. I've restarted the computer and changed the password several times, but the Touch ID setup still won't accept it. Has anyone found a solution?
2 Answers
If you migrated your files or account from another computer, the migration may have brought over something that is interfering with password authentication for that profile. Try creating a fresh user account and setting up Touch ID there. If it works, back up your files and consider using the new account rather than repeatedly resetting the password. Reinstalling macOS or fully wiping the Mac may not fix it if the same problematic profile is migrated back afterward.
Since the machine is new and the password is accepted everywhere else, this sounds more like a software or account-profile problem than a bad keyboard or incorrect password. Make sure macOS is fully updated, and if a clean user account doesn’t solve it for your normal account, have Apple support inspect the Mac in person. A service appointment is probably more useful than continuing to wipe the computer, especially if the problem survives a factory reset.

I tested this on a new account and Touch ID worked immediately. I also tried resetting the password, Recovery Mode, reinstalling macOS, and a factory reset, but the issue returned after migrating the old profile again.