re: <https://www.vhlcentral.com/home>

I have full access to this site with user name and password yet WinHTTrack
only runs for about 30 seconds and I receive a string of errors like: 
Error:  "Forbidden" (403) at link
<https://assets.maestro.vhlcentral.com/assets/blitzer/images/ui-bg_flat_75_ffffff_40x100.png>
(from
<https://assets.maestro.vhlcentral.com/assets/blitzer/jquery-ui-1.8.11.custom-8d6f5081e8d8e4c409cae8abbb4b79d1c7c14eb5042e6d7327b8b7cf7fc96e38.css>)
This is a school textbook site and my only guess is the "maestro" above is a
clue since it is a Spanish language class and 'Maestro' is 'teacher' in
English. I don't need teacher access, only what I can see on my normal
browser. 

I added my user name and PW on the appropriate window...

Can anyone help?