It seems that Option Value Manager has some bugs.

"Copy to ALL Products where Option Name and Value" and other functions don't work.
I copied options_values_manager.php from zen cart v1.5.5, then it works.

I checked some files and find a Typo, but still I can't make them work...


This is the Typo,

zen-cart-v1.5.6a-01042019/admin/options_values_manager.php

Line262
if ($check_previous->RecorCount() < 1) {