You would get this error when clicking on "reset password" from your password recovery mail, if already an hour has passed after the mail was received.
As the password reset token stays valid for an hour only, in case you get this error, you would need to regenerate a fresh password recovery mail.
To do so, click on LOGIN WITH EMAIL (if you are using the Android app) or "login with email and password" (if you are using the iOS app or website) followed by "forgot password", where you can type your email ID and submit to get the mail.