Accessed None When Trying to Read Property

[Kevam]

Hey guys,
We are making a college project and one of my friends had this template Story Advanced Template and so we added this to our project. It has various functions like inventory, inspection screen, menu system, etc.
We set the player classes and game modes and so on, and I am able to use the inspect system of the template in our level, but the problem comes when I try to open main menu or inventory or basically any other menu system.
It gives these errors :

However, when I open the demo level of the template in the same project, the menus all open without any problem. I have extremely shallow knowledge of the blueprint system and some knowledge of OOP but these blueprint classes are very layered and distributed in different places so I don’t understand how and where to start checking for a fix.
This is where the error leads to when I double click on the log:

[Dejan33]

This menu pawn (and probably many other things) are likely in the demo level. Try adding this menu pawn asset to your own level. Find it in the demo level - right click - browse to asset and than drop it in your level.

[Kevam]

Thanks for the reply! Apparently, I was supposed to add the demo level itself as a persistent level and then hide it somewhere in my active level to access the menu blueprints.