Little help with wordpress authors page!

I’m using GK Portfolio theme and I’m trying to link the authors to their profiles.
The problem is that when the author doesn’t have any posts, it shows a “page not found”. I’m not very experienced in coding but I think it’s something in the author.php file in the theme.

And also, the authors link in the post doesn’t go to their profiles. It just refreshes the page.

Anyone can help here? ??

Thanks