Lesson page does’t work (2ird theme)

My lesson page doesn’t work, it just keeps loading like forever

First theme: https://ww.wp.xz.cn/support/topic/lesson-page-doest-work/

My log:

TypeError: $(…)[0] is undefined custom.min.js:4:4131
data.currentGw is undefined popup.js:157
Unchecked lastError value: Error: Could not establish connection. Receiving end does not exist. ExtensionCommon.jsm:304

view-source:http://mir-pigmalion.ru/wp-content/themes/massive-dynamic/assets/js/custom.min.js?ver=5.3

This file is associated with the header display function in my theme. I was trying to delete all strings in this file (custom.min.js), problem had fixed. But my theme can`t display the header without this strings :). How can I find out more precisely where the conflict is? I want to display header correct on plugin pages.

• This topic was modified 8 years, 6 months ago by wamure.
• This topic was modified 8 years, 6 months ago by wamure.

The page I need help with: [log in to see the link]