Note that this error is specific to the website dashboard login:
If you are seeing this message, it means you do not have an administrator's account.
Only account owners can access the website dashboard.
If you have been assigned a license, you need to use the credentials you were sent to log into the installed PDF2XL Desktop Application.
If you haven't yet downloaded it, you can do so here: https://pdf2xl.com/download/pdf2xl.msi
(link does not work for versions below 8.6)