Quote Originally Posted by zamzom View Post
[ZC 1.5.8][PHP 8.0][MySQL 10.3]
The bold part is where your problem lies. I haven't updated this plugin for 1.5.8 (nor php 8.x) and at the moment have no plans for it.

The plugin works fine on 1.5.7 (it was built on request by one of my clients and used by multiple) but needs a thorough code review for 1.5.8 because of all the changes introduced in that version.