1- From your WordPress host-Go to Highend sidebar and select “Highend Options” from drop down menu.
2- At the very bottom you’ll see a window called “Custom CSS”
3- At the top left corner of that window, type in (style.css) without parentheses.
5- Save Changes!
6- Refresh site (Log out and log back in)
7- Go back to WordPress host, “Highend Options” import demos and retry.
This worked for me without a problem, good luck!