Remove Child and null

Sorry for making a dud thread before (don’t know how to remove it)
My problem is i am trying to make a MiniMap and make it update properly when the level changes.
Ive spent about 4 hours trying to make it work with just a next and previous button and not return an error.
See the attached .rar feel free to use any of it (Done mostly by learning from everyone here, Thanks to all)
I am unsure if this is even a proper way to do this.
Below are all the project files and folders. (not that large, under 100lines Total)
Any Help/suggestions/tips are greatly appreciated.