There are two reasons for this error.

Reason 1 - The email being entered in to reset the password is not the email on the Primary Persona of that user. Another user in your database can tell you the correct email to use, or an Admin can reset the password using the steps here: How to reset a user's password in eTapestry.

Reason 2 - There are two emails on the Primary Persona of the user account. If there are two emails, it will not know which to look at. The password will need to be reset by the Admin using these steps: How to reset a user's password in eTapestry. Once the password has been reset and the user has successfully logged in, one of the emails should be deleted from that Persona to prevent issues in the future.
  1. Click Management
  2. Click My User
  3. Click Personas
  4. Scroll down to the Email field and delete one of the email addresses
  5. Click Save And