I activated MyBB 2fa (the new 1.8.4 feature), and now my admin account is locked out of the acp. It keeps saying the code is invalid. How can I set a recovery pin, or remove it? I tried updating the secret column in mybb_user to no avail
What DB server type are you using? If it's Postgres or SQLite, there's a known bug which we should be releasing a patch for soon.
We strongly recommend using MySQL if you aren't already, because MyBB is tested more actively on it.
Is the error
The code was incorrect, you're logged out now
If not, please screenshot the error and post here.
And are you surely entering a correct code? Have you followed the instructions and saved recovery codes and/or scanned the QR code?
As for the database, there is no "secret" column in mybb_users table.. You should empty 2fasecret column in mybb_adminoptions table.