Cannot set up Touch ID, unlock System Preferences, or reinstall Big Sur [2020 Intel MBA i3]

Question

Today I have upgraded my 2020 Intel MacBook Air to Big Sur (11.1). Since upgrading, I am unable to unlock the "lock" in the System Preferences panels that require it (the window "jiggles" even with the right password) and I am unable to set up Touch ID (after entering the password it doesn't prompt me to register a new fingerprint).

I saw in other answers that others used the resetpassword utility from Recovery mode, so I did this too. The problem persisted even after changing the password. The linked answer recommends creating a new admin user, but I cannot do that as I can't unlock the "padlock" in System Preferences to do so. I also reset NVRAM to no avail.

Ultimately, I chose to reinstall Big Sur from recovery, but entering the password to unlock the disk does not "do" anything, as in, the password entry window simply fades out but the installation does not move forward and I am still able to click on the "unlock" button again.

I was wondering if anyone knew how I can solve this issue. Since the computer is relatively new, I don't mind completely resetting it.

Thank you very much.

Answer 1

Answering my own question, but... resetting the SMC (as explained here https://support.apple.com/en-ca/HT201295) ended up doing the trick for me.

Answer 2

The fix for me was actually the steps before resetting the SMC, so I didn't need to do an SMC reset. Here are those simple steps:

1. Shut down your Mac.
2. Press and hold the power button for 10 seconds, then release the button.
3. Wait a few seconds, then press the power button to turn on your Mac.

Source: How to reset the SMC of your Mac by Apple

Worth noting I did first remove all existing Touch ID fingerprints from my Mac before doing this.

UPDATE: It's also worth remembering that Touch ID is disabled for the first login after a shutdown

Answer 3

Encountered the same issue w/ System Preferences. An SMC reset fixed.

Answer 4

You can try to restore to factory settings by installing the version of macOS that came with your MacBook Air instead of Big Sur.

Here's how you do it:

1. Turn off your Mac
2. When you start it hold CMD+OPTION+R
3. Connect to the internet if it ask for an internet connection
4. When you are in internet recovery mode, open disk utility and erase the disk
5. Exit disk utility and install a new copy of macOS