1. Created structure:
2. Create a libs folder in the development environment and copy the button.lua file there through the explorer.
3. I didn't know that it was enough to update the folder and then the file would appear in the structure. So I added it via Link Existing File.
As a result, if we reopen the project, we will get a duplicate file in the project structure.
And also in the project file there will be 2 records about one file:
<folder name = "libs">
<file source = "assets/libs/button.lua"/>
<file name = "assets/libs/button.lua"/>
I think that new users have a misunderstanding why this is happening. And in fact, this is an incorrect organization of the project file. It is worth checking for duplicate file entries and leaving one of them.