Problems with button nodes in start menu not being found

4

I was messing around a bit with button placement in a start menu, using separators and boxcontainers.
I also added an animated camera that would scroll down top to bottom, then stop and have the buttons appear.
Tried the animation a few times and it worked with no problems. Added some separators, containers etc and started messing around with button placement. Now, the scene does not load and the script has error messages, one for each button saying the they can not be found. I tried moving the buttons back to their old boxcontainer but it did not do anything.

I’m very new to coding. Would appreciate if someone could explain what has happened! Thank you!

E 0:00:01:0282 main_menu.gd:4 @ _ready(): Node not found: “start_button” (relative to “/root/Main_menu”).
<C++ Error> Method/function failed. Returning: nullptr
<C++ Source> scene/main/node.cpp:1651 @ get_node()
main_menu.gd:4 @ _ready()

Did you save your script after changing the paths to their correct position?

(the (*) after the main_menu.gd file means that there are unsaved changes)

You can also drag the nodes in question into the script editor to get the respective $path string