> HTTrack3.48-21+htsswf+htsjava launched on Fri, 27
> Nov 2015 12:33:14 at <http://www.york.ac.uk/> +*.png
> +*.gif +*.jpg +*.jpeg +*.css +*.js
> -ad.doubleclick.net/* -mime:application/foobar
> (winhttrack
> -qwC2%Ps2u1%s%uN0%I0p3DaK0H0%kf2A25000%f#f -F
> "Mozilla/4.5 (compatible; HTTrack 3.0x; Windows 98)"
> -%F "<!-- Mirrored from %s%s by HTTrack Website
> Copier/3.x [XR&CO'2014], %s -->" -%l "en, *"
> <http://www.york.ac.uk/> -O1 "C:\My Web Sites\005"
> +*.png +*.gif +*.jpg +*.jpeg +*.css +*.js
> -ad.doubleclick.net/* -mime:application/foobar )
> Information, Warnings and Errors reported for this
> mirror:
> note: the hts-log.txt file, and hts-cache folder,
> may contain sensitive information,
>  such as username/password authentication for
> websites mirrored in this project
>  do not share these files/folders if you want these
> information to remain private
> 12:33:15 Error:  "Connect Error" (-4) after 2
> retries at link www.york.ac.uk/robots.txt (from
> primary/primary)
> 12:33:16 Warning:  Retry after error -4 (Connect
> Error) at link www.york.ac.uk/ (from
> primary/primary)
> 12:33:17 Warning:  Retry after error -4 (Connect
> Error) at link www.york.ac.uk/ (from
> primary/primary)
> 12:33:18 Error:  "Connect Error" (-4) after 2
> retries at link www.york.ac.uk/ (from
> primary/primary)
> 12:33:18 Warning:  No data seems to have been
> transferred during this session! : restoring
> previous one!
> 

Try to Disable robots.txt in the settings for your project. If that fails,
you're being blocked for attempting to copy a site that the administrator
doesnt want you to copy :)