In old version of theme Twentyfourteen, I could get next and previous post for same category by changing like this in template-tags.php:
$previous = ( is_attachment() ) ? get_post( get_post()->post_parent ) : get_adjacent_post( true, '', true ); $next = get_adjacent_post( true, '', false );
But after update to the latest theme, I cannot get it to work. I tried to google but nothing works for me till now. I hope anyone experienced this problem could help me.