Hi,
I don't think it's related to the 4.2.0. However, it's probably related to your view override not compatible with recent versions of Joomla.
One year ago, we had to add modifications in the view file category/listing.php for a new version of Joomla at that time. So if you have a view override from the 3.0.0 on that file the problem is likely from there.
So check for the file templates/YOUR_TEMPLATE/html/com_hikashop/category/listing.php via FTP and if you find it, try renaming it to deactivate it. That could very well fix the problem.