Can they get to the One-time code screen?

If they aren't then the user is entering the wrong email or password.
Resolution: Check Account details

Does a QR code appear?

If the Code appears then they have not yet linked their CMMS account to an Authentication App.
Resolution: If The QR code appears

Do they have an Authentication App?

If they do not have one, then the user may not have stored the code.
Resolution: If they don't have an Authenticator App

When aiming the camera in the authenticator app, does it work?

Is the QR code slightly covered or obscured?
Resolution: The Authentication App isn't scanning the QR code

Are they trying to set up the account on 2 Authentication apps?

We don't support multiple users having access to the same account.
Resolution: Informing the User the security system doesn't allow us to have multiple devices storing the OTP.

Do they actually have an account?

If they don't, set up an account.
Resolution: Check Account details

Is their account inactive?

If their account is inactive they won't be able to sign in.
Resolution: Check Account details

Are they a system user or a non-system user?

If they are a non-system user they won't be able to sign in or receive the forgotten password email.
Resolution: Check Account details

Is their account blocked?

Unblock their account.
Resolution: Check Account details

Are they using their camera to scan?

This won't save the 2FA as an account, and won't allow them to enter a valid code.
Resolution: If they don't have an Authenticator App

Does their Authentication App have multiple accounts saved?

They could be entering the wrong account code.
Resolution: The Authentication App has multiple saved accounts

Is the Authentication App legitimate (Microsoft/Google/Etc)

They may need to get a new Authenticator.
Resolution: If they don't have an Authenticator App

Is their Phone Very Old?

Some Phones may be unable to use an authenticator such as a dumb phone.
Resolution: Inform the user they will need to use a different device to set up Authentication.

Are their Apps updated?

Some issues may arrise if the users phone is not updated correctly.
Resolution: Inform the user they will need to update their apps.

Has the user Jail broken the device?

Jail broken phones maybe unable to correctly complete the steps, and assisting them may
Resolution: Do not attempt to resolve this for the user as Jail broken phones may have unique bugs.

Is the phone using automatic time?

Auth0 MFA relies on Automatic date and time because it is a Time-Based One-Time Password (TOTP)
Resolution: Automatic date and time

Go to User's Profile

Check they have an email

Check the account is unlocked

Check the account is Active

Check the account is not a mailbox account

Check the email system is actually sending a notification

Access Auth0

Naviagate to the User

User Management menu > Users
Search for email address of User
Click 'Reset MFA'