I'm having an issue with adding this code to ContentView as described in the lesson:

@FetchRequest(entity: Student.entity(), sortDescriptors: []) var students: FetchedResults<Student>

It is giving the error "Use of undeclared type Student"

After searching the internet some, I found a post that suggested:

1. right-clicking the Bookworm.xcdatamodeld file
2. select 'Show in Finder'
3. drag the .xcdatamodel file into your project (Note: the lack of the letter 'd' on the end of the file extension)
4. delete the old xcdatamodeld file from your project

This appears to have work, as the error went away. But why did this work? Why couldn't Xcode recognize the Student entity that I created in my xcdatamodeld file?

Has anybody else experienced this? I'd like to understand better what happened.

Thanks for the response! I spent half the day yesterday googling/trying different methods until the one that you suggested finally did the trick.

Thanks byaruhaf, that tricked solved it for me too!

This did not work for me.. im still getting the same errors

Thanks! Worked for me.

For me, this fixed the issue but created another: ! Cannot preview in this file -- Bookworm.app may have crashed. Check...

Unfortunately, I am experiencing the same problem as @smithi01, after following the steps suggested by @byaruhaf. I've been able to narrow the problem down somewhat - XCode compiles and runs the code just fine until i add the list code:

List {
    ForEach(students, id: \.id) { student in
        Text(student.name ?? "Unknown")
    }
}

I've tried copying and pasting the code, typing out the code, closing and re-opening XCode, restarting the computer - nothing works. XCode only displays the "Cannot preview this file - Bookworm.app may have crashed" error message. XCode 11.6, Mac OS Catalina 10.15.5.

UPDATE for anyone else having this problem. I was previewing the app in XCode's canvas. Can't remember where i came across this, but I saw somewhere that the canvas preview and Core Data don't always get along - something to do with errors when attempting to load the data. At any rate, I switched to using the simulator (as Paul was showing in his video) and it worked.

Thank you byaruhaf - it works!