Hide Sidebar item "Uncaught TypeError: Cannot read property 'contains' of undefined"

I’m just preparing a quick demo for a loan management system project. I came across to free admin template but I cannot seem to hide some of the items on the sidebar. I get error mentioned on the subject whenever I hide any list item on the sidebar. Does customization requires purchase of license or what?

Regards

Hard to answer since you do not refer to version / framework.

Its CoreUI v3.2.0.

I have not integrated to any framework. Just installed it based on instruction from official site and github.