Hi there,
Thanks for this update. I am upgraded from v4 on 1.55e zencart, so perhaps it is upgrade related. Everything else seems okay. I get a blank page for adding a second image, and the following in error log:-

[17-Oct-2017 18:26:35 UTC] PHP Fatal error: Uncaught Error: Call to undefined function find_additional_images() in /home/****/public_html/****/includes/ih_manager.php:119
Stack trace:
#0 /home/*****/public_html/****/image_handler.php(53): require()
#1 {main}
thrown in /home/****/public_html/****/includes/ih_manager.php on line 119[/QUOTE]


But I am using the beta and latest version, so perhaps this is not an issue in pending download version. I did overwrite of files and tried finding that function with developer tool kit. Everything else seems okay, am using colorbox if it makes any difference and it installed perfectly.