Ok, i strictly followed your tutorial, here are my first observations:
The first time i opened the editor everything was fine.
Everything works fine until the "Try the track" part, when i click this button the game doesn't load (I selected the game’s executable). But if i open the game myself the track works.
When we open the editor the main window was white maybe there will be a simple loading screen in the future
?
When I try to open tracks that i saved the editor crash, so i can only create new tracks.
Then I think you should create a cancel button at some places for example "Create a new track":
We can't see the cancel button everywhere
You should make some windows be smaller and add a scrollbar instead.
That's all for now.
The editor is great !