You can reset your PayDashboard password by going to the log in page and pressing the "Forgotten details" button. On the next page please enter the email address that is assigned to your account and press the "Reset Password" button. You will then receive an email with a link to reset your password.
If you receive an error after changing your password, It is possible that your web browser has saved your previous password and this is auto populating when you are trying to enter your new password. We would suggest deleting your saved passwords on your browser or possibly trying a different Web Browser like Google Chrome for example.