fatal error call to undefined function hb_option() at line 13 in the header.php

Hi, not a WordPress expert but trying to get there. I have been working happily away with Visual Composer with my HB HighEnd theme and I keep getting this error:

fatal error call to undefined function hb_option() in the header.php on line 13

I have the new version 4.10 of Visual Composer which I purchased from them but the problem was there before that update.

Many thanks
John